WoW64 - Revision history

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2024-02-26T12:44:42Z

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← Previous revision		Revision as of 12:44, 26 February 2024
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	# A dll that allows 32-bit x86 instructions to be executed, which varies by [[instruction set architecture]].		# A dll that allows 32-bit x86 instructions to be executed, which varies by [[instruction set architecture]].
	#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>		#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>
	#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|~~website=web.~~archive~~.org \|~~date=26 ~~April 2010~~}} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>		#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|date=26 April 2010\|archive-url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|archive-date=2010-04-26 }} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>
	#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref name="wow64-dlls"/>		#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref name="wow64-dlls"/>

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	The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.		The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.

	The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>		The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com\|date=2 February 2023 }}</ref>
	*{{#tag:code\|%SystemRoot%\system32\catroot}}		*{{#tag:code\|%SystemRoot%\system32\catroot}}
	*{{#tag:code\|%SystemRoot%\system32\catroot2}}		*{{#tag:code\|%SystemRoot%\system32\catroot2}}

Artoria2e5: little wine dll presence note

2023-12-31T06:28:47Z

little wine dll presence note

← Previous revision		Revision as of 06:28, 31 December 2023
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	* [[ARM64]] versions of [[Windows 10]], [[Windows 11]] and [[Windows Server 2022]].		* [[ARM64]] versions of [[Windows 10]], [[Windows 11]] and [[Windows Server 2022]].

	[[Wine (software)\|Wine]], which is not a Microsoft product, also offers experimental WoW64 in its x64 version.<ref>{{Cite web \|last=Conway \|first=Adam \|date=2023-01-25 \|title=Wine 8.0 released with better controller compatibility, experimental WoW64 support, and more \|url=https://www.xda-developers.com/wine-80-released/ \|access-date=2023-04-16 \|url-status=live \|archive-url=https://web.archive.org/web/20230416110310/https://www.xda-developers.com/wine-80-released \|archive-date=2023-04-16 \|website=XDA Developers}}</ref>}} WoW64 aims to take care of many of the differences between 32-bit Windows and 64-bit Windows, particularly involving structural changes to Windows itself.		[[Wine (software)\|Wine]], which is not a Microsoft product, also offers experimental WoW64 in its x64 version.<ref>{{Cite web \|last=Conway \|first=Adam \|date=2023-01-25 \|title=Wine 8.0 released with better controller compatibility, experimental WoW64 support, and more \|url=https://www.xda-developers.com/wine-80-released/ \|access-date=2023-04-16 \|url-status=live \|archive-url=https://web.archive.org/web/20230416110310/https://www.xda-developers.com/wine-80-released \|archive-date=2023-04-16 \|website=XDA Developers}}</ref> Wine also has {{code\|wow64.dll}}, {{code\|wow64win.dll}}, and {{code\|wow64cpu.dll}}.}} WoW64 aims to take care of many of the differences between 32-bit Windows and 64-bit Windows, particularly involving structural changes to Windows itself.

	==Translation libraries==		==Translation libraries==

Artoria2e5: /* Registry and file system */ cite-fixing

2023-12-31T06:22:15Z

Registry and file system: cite-fixing

← Previous revision		Revision as of 06:22, 31 December 2023
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	The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>		The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>
	*%SystemRoot%\system32\catroot		*{{#tag:code\|%SystemRoot%\system32\catroot}}
	*%SystemRoot%\system32\catroot2		*{{#tag:code\|%SystemRoot%\system32\catroot2}}
	*%SystemRoot%\system32\driverstore (redirected on Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP)		*{{#tag:code\|%SystemRoot%\system32\driverstore}} (redirected on Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP)
	*%SystemRoot%\system32\drivers\etc		*{{#tag:code\|%SystemRoot%\system32\drivers\etc}}
	*%SystemRoot%\system32\logfiles		*{{#tag:code\|%SystemRoot%\system32\logfiles}}
	*%SystemRoot%\system32\spool		*{{#tag:code\|%SystemRoot%\system32\spool}}

	The redirection helps to keep 32-bit applications working without them needing to be aware of the WoW64 status.<ref name=FSR/> If a 32-bit application wants to access the real <code>%SystemRoot%\System32</code>, it can do so through the pseudo-directory <code>%SystemRoot%\sysnative</code> since Windows Vista.<ref name=FSR/> Detection of Wow64 status is possible via {{code\|IsWow64Process()}}.		The redirection helps to keep 32-bit applications working without them needing to be aware of the WoW64 status.<ref name=FSR/> If a 32-bit application wants to access the real <code>%SystemRoot%\System32</code>, it can do so through the pseudo-directory <code>%SystemRoot%\sysnative</code> since Windows Vista.<ref name=FSR/> Detection of Wow64 status is possible via {{code\|IsWow64Process()}}.
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	There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>		There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>

	A few new directories are also found on ARM64, where WOW64 handles not only the running of 32-bit x86 programs, but also 32-bit ARM programs, which uses {{code\|SysArm32}} instead. ARM64 also supports the so-called CHPE "compiled-hybrid-PE", which has ARM64 code in a x86 dll container (for more efficient, emulation-free compatibility); these dlls are found in {{code\|SyCHPE32}}.<ref name="wbenny">{{cite web \|last1=Beneš \|first1=Petr \|title=WoW64 internals: re-discovering Heaven's Gate on ARM \|url=https://wbenny.github.io/2018/11/04/wow64-internals.html~~#windowssychpe32--windowssyswow64~~ \|website=mindless-area (wbenny.github.io) \|date=November 04, 2018}}</ref>		A few new directories are also found on ARM64, where WOW64 handles not only the running of 32-bit x86 programs, but also 32-bit ARM programs, which uses {{code\|SysArm32}} instead. ARM64 also supports the so-called CHPE "compiled-hybrid-PE", which has ARM64 code in a x86 dll container (for more efficient, emulation-free compatibility); these dlls are found in {{code\|SyCHPE32}}.<ref name="wbenny">{{cite web \|last1=Beneš \|first1=Petr \|title=WoW64 internals: re-discovering Heaven's Gate on ARM \|url=https://wbenny.github.io/2018/11/04/wow64-internals.html\|website=mindless-area (wbenny.github.io) \|date=November 4, 2018}}</ref><!-- SysX8664 exists in dll, but does not seem to be used (hybrid binaries are used for ARM64EC<>x64 interop instead?) -->

	==Application compatibility==		==Application compatibility==

Artoria2e5: /* Translation libraries */ huh?

2023-12-31T06:18:12Z

Translation libraries: huh?

← Previous revision		Revision as of 06:18, 31 December 2023
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	#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>		#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>
	#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|website=web.archive.org \|date=26 April 2010}} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>		#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|website=web.archive.org \|date=26 April 2010}} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>
	#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref		#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref name="wow64-dlls"/>
	="wow64-dlls"/>

	==Registry and file system==		==Registry and file system==

Artoria2e5: Roll /* Architecture / into / Translation libraries */

2023-12-31T06:17:49Z

Roll Architecture: into Translation libraries

← Previous revision		Revision as of 06:17, 31 December 2023
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	==Translation libraries==		==Translation libraries==
	The WoW64 [[subsystem]] comprises a lightweight [[compatibility layer]] that has similar interfaces on all 64-bit versions of Windows. It aims to create a 32-bit environment that provides the interfaces required to run unmodified 32-bit Windows applications on a 64-bit system. WOW64 is implemented using several DLLs, some of which include: <ref name="wow64-dlls">{{cite web \|title=WOW64 Implementation Details \|url=https://msdn.microsoft.com/en-us/library/windows/desktop/aa384274(v=vs.85).aspx \|access-date=2018-04-21 \|work=Microsoft}}</ref>		The WoW64 [[subsystem]] comprises a lightweight [[compatibility layer]] that has similar interfaces on all 64-bit versions of Windows. It aims to create a 32-bit environment that provides the interfaces required to run unmodified 32-bit Windows applications on a 64-bit system. WOW64 is implemented using several DLLs, some of which include:<ref name="wow64-dlls">{{cite web \|title=WOW64 Implementation Details \|url=https://msdn.microsoft.com/en-us/library/windows/desktop/aa384274(v=vs.85).aspx \|access-date=2018-04-21 \|work=Microsoft}}</ref>
	# <code>Wow64.dll</code>, the core interface to the [[Architecture of Windows NT\|Windows NT kernel]] that [[Thunk (compatibility mapping)\|translates]] (thunks) between 32-bit and 64-bit calls, including [[pointer (computer programming)\|pointer]] and [[call stack]] manipulations		# <code>Wow64.dll</code>, the core interface to the [[Architecture of Windows NT\|Windows NT kernel]] that [[Thunk (compatibility mapping)\|translates]] (thunks) between 32-bit and 64-bit calls, including [[pointer (computer programming)\|pointer]] and [[call stack]] manipulations
	# <code>Wow64win.dll</code>, which provides the appropriate entry-points for 32-bit applications (win32k thunks)		# <code>Wow64win.dll</code>, which provides the appropriate entry-points for 32-bit applications (win32k thunks)
			# A dll that allows 32-bit x86 instructions to be executed, which varies by [[instruction set architecture]].
	# <code>Wow64cpu.dll</code>, which takes care of switching the processor from 32-bit to 64-bit mode. This is used in [[x86-64]] implementations of Windows only.
			#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>

			#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|website=web.archive.org \|date=26 April 2010}} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>
	Other DLLs and binaries are included for [[IA-64\|Itanium]] and [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]] architectures to provide emulation to [[x86]] or for 32-bit entry points if the architecture has a native 32-bit operating mode.
			#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref

			="wow64-dlls"/>
	==Architectures==
	Despite its outwardly similar appearance on all versions of 64-bit Windows, WoW64's implementation varies depending on the target [[instruction set architecture]]. For example, the version of 64-bit Windows developed for the [[Intel]] [[Itanium 2]] processor (known as the [[IA-64]] architecture) uses <code>Wow64win.dll</code> to set up the emulation of [[x86]] instructions within the Itanium 2's unique [[instruction set]]. This emulation is a much more computationally expensive task than the <code>Wow64win.dll</code>'s functions on the [[x86-64]] architecture, which switches the processor hardware from its 64-bit mode to compatibility mode when it becomes necessary to execute a 32-bit [[thread (computer science)\|thread]], and then handles the switch back to 64-bit mode.

	==Registry and file system==		==Registry and file system==
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	There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>		There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>

			A few new directories are also found on ARM64, where WOW64 handles not only the running of 32-bit x86 programs, but also 32-bit ARM programs, which uses {{code\|SysArm32}} instead. ARM64 also supports the so-called CHPE "compiled-hybrid-PE", which has ARM64 code in a x86 dll container (for more efficient, emulation-free compatibility); these dlls are found in {{code\|SyCHPE32}}.<ref name="wbenny">{{cite web \|last1=Beneš \|first1=Petr \|title=WoW64 internals: re-discovering Heaven's Gate on ARM \|url=https://wbenny.github.io/2018/11/04/wow64-internals.html#windowssychpe32--windowssyswow64 \|website=mindless-area (wbenny.github.io) \|date=November 04, 2018}}</ref>

	==Application compatibility==		==Application compatibility==
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	==Performance==		==Performance==
		⚫	According to Microsoft, 32-bit software running under WOW64 (x64) has similar performance to executing under 32-bit Windows, but with fewer threads possible. On a non-x64 system, WOW64 incurs a performance overhead due to the software emulation involved.<ref name="VSdocLAA">{{cite web
	{{Expand section\|date=August 2013}}

⚫	According to Microsoft, 32-bit software running under WOW64 has similar performance to executing under 32-bit Windows, but with fewer threads possible ~~and~~ ~~other~~ ~~overheads~~.<ref name="VSdocLAA">{{cite web
	\|url=http://msdn.microsoft.com/en-gb/library/windows/desktop/aa384219(v=vs.85).aspx		\|url=http://msdn.microsoft.com/en-gb/library/windows/desktop/aa384219(v=vs.85).aspx
	\|title= Performance and Memory Consumption Under WOW64		\|title= Performance and Memory Consumption Under WOW64

Artoria2e5: OS list too long, just pop in a note instead.

2023-12-31T05:49:08Z

OS list too long, just pop in a note instead.

← Previous revision		Revision as of 05:49, 31 December 2023
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	\| website = {{URL\|https://docs.microsoft.com/en-us/windows/desktop/WinProg64/running-32-bit-applications}}		\| website = {{URL\|https://docs.microsoft.com/en-us/windows/desktop/WinProg64/running-32-bit-applications}}
	}}		}}
	In [[computing]] on [[Microsoft]] platforms, '''WoW64''' ('''W'''indows 32-bit '''o'''n '''W'''indows '''64'''-bit) is a subsystem of the [[Microsoft Windows\|Windows]] [[operating system]] capable of running [[32-bit]] applications on 64-bit Windows.<ref>{{Cite web \|author1=QuinnRadich \|author2=DCtheGeek \|author3=msatranjr \|date=2020-08-19 \|title=WOW64 Implementation Details \|url=https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|access-date=2023-04-16 \|archive-date=2023-04-16 \|archive-url=https://web.archive.org/web/20230416160609/https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|website=learn.microsoft.com}}</ref> It is included in all [[64-bit]] versions of ~~Windows—including~~ [[Windows XP Professional x64 Edition]], [[IA-64]] and [[x86-64\|x64]] versions of [[Windows Server 2003]]~~, as well as~~ [[x64]] versions of [[Windows Vista]], [[Windows Server 2008]], [[Windows 7]], [[Windows 8]], [[Windows Server 2012]], [[Windows 8.1]], [[Windows 10]], [[Windows Server 2016]], [[Windows Server 2019]], [[Windows 11]], [[Windows Server 2022]], and [[Wine (software)\|Wine]].<ref>{{Cite web \|last=Conway \|first=Adam \|date=2023-01-25 \|title=Wine 8.0 released with better controller compatibility, experimental WoW64 support, and more \|url=https://www.xda-developers.com/wine-80-released/ \|access-date=2023-04-16 \|url-status=live \|archive-url=https://web.archive.org/web/20230416110310/https://www.xda-developers.com/wine-80-released \|archive-date=2023-04-16 \|website=XDA Developers}}</ref> as well as [[ARM64]] versions of [[Windows 10]], [[Windows 11]] and [[Windows Server 2022]], except in Windows Server [[Server Core]] where it is an optional component, and Windows [[Nano Server]] where it is not included. WoW64 aims to take care of many of the differences between 32-bit Windows and 64-bit Windows, particularly involving structural changes to Windows itself.		In [[computing]] on [[Microsoft]] platforms, '''WoW64''' ('''W'''indows 32-bit '''o'''n '''W'''indows '''64'''-bit) is a subsystem of the [[Microsoft Windows\|Windows]] [[operating system]] capable of running [[32-bit]] applications on 64-bit Windows.<ref>{{Cite web \|author1=QuinnRadich \|author2=DCtheGeek \|author3=msatranjr \|date=2020-08-19 \|title=WOW64 Implementation Details \|url=https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|access-date=2023-04-16 \|archive-date=2023-04-16 \|archive-url=https://web.archive.org/web/20230416160609/https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|website=learn.microsoft.com}}</ref> It is included in all [[64-bit]] versions of Windows, except in Windows Server [[Server Core]] where it is an optional component, and Windows [[Nano Server]] where it is not included.{{efn\|1=Specifically:
			* [[Windows XP Professional x64 Edition]]
			* [[IA-64]] and [[x86-64\|x64]] versions of [[Windows Server 2003]]
			* [[x64]] versions of [[Windows Vista]], [[Windows Server 2008]], [[Windows 7]], [[Windows 8]], [[Windows Server 2012]], [[Windows 8.1]], [[Windows 10]], [[Windows Server 2016]], [[Windows Server 2019]], [[Windows 11]], [[Windows Server 2022]]
			* [[ARM64]] versions of [[Windows 10]], [[Windows 11]] and [[Windows Server 2022]].

			[[Wine (software)\|Wine]], which is not a Microsoft product, also offers experimental WoW64 in its x64 version.<ref>{{Cite web \|last=Conway \|first=Adam \|date=2023-01-25 \|title=Wine 8.0 released with better controller compatibility, experimental WoW64 support, and more \|url=https://www.xda-developers.com/wine-80-released/ \|access-date=2023-04-16 \|url-status=live \|archive-url=https://web.archive.org/web/20230416110310/https://www.xda-developers.com/wine-80-released \|archive-date=2023-04-16 \|website=XDA Developers}}</ref>}} WoW64 aims to take care of many of the differences between 32-bit Windows and 64-bit Windows, particularly involving structural changes to Windows itself.

	==Translation libraries==		==Translation libraries==
Line 95:		Line 101:
	*[[Windows on Windows]]		*[[Windows on Windows]]

			== Notes==
			{{notelist}}
	==References==		==References==
	{{Reflist\|30em}}		{{Reflist\|30em}}

Bender the Bot: /* top */HTTP to HTTPS for Wayback Machine, replaced: http://web.archive.org/ → https://web.archive.org/

2023-05-13T15:32:53Z

top: HTTP to HTTPS for Wayback Machine, replaced: http://web.archive.org/ → https://web.archive.org/

← Previous revision		Revision as of 15:32, 13 May 2023
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	\| website = {{URL\|https://docs.microsoft.com/en-us/windows/desktop/WinProg64/running-32-bit-applications}}		\| website = {{URL\|https://docs.microsoft.com/en-us/windows/desktop/WinProg64/running-32-bit-applications}}
	}}		}}
	In [[computing]] on [[Microsoft]] platforms, '''WoW64''' ('''W'''indows 32-bit '''o'''n '''W'''indows '''64'''-bit) is a subsystem of the [[Microsoft Windows\|Windows]] [[operating system]] capable of running [[32-bit]] applications on 64-bit Windows.<ref>{{Cite web \|author1=QuinnRadich \|author2=DCtheGeek \|author3=msatranjr \|date=2020-08-19 \|title=WOW64 Implementation Details \|url=https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|access-date=2023-04-16 \|archive-date=2023-04-16 \|archive-url=~~http~~://web.archive.org/web/20230416160609/https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|website=learn.microsoft.com}}</ref> It is included in all [[64-bit]] versions of Windows—including [[Windows XP Professional x64 Edition]], [[IA-64]] and [[x86-64\|x64]] versions of [[Windows Server 2003]], as well as [[x64]] versions of [[Windows Vista]], [[Windows Server 2008]], [[Windows 7]], [[Windows 8]], [[Windows Server 2012]], [[Windows 8.1]], [[Windows 10]], [[Windows Server 2016]], [[Windows Server 2019]], [[Windows 11]], [[Windows Server 2022]], and [[Wine (software)\|Wine]].<ref>{{Cite web \|last=Conway \|first=Adam \|date=2023-01-25 \|title=Wine 8.0 released with better controller compatibility, experimental WoW64 support, and more \|url=https://www.xda-developers.com/wine-80-released/ \|access-date=2023-04-16 \|url-status=live \|archive-url=https://web.archive.org/web/20230416110310/https://www.xda-developers.com/wine-80-released \|archive-date=2023-04-16 \|website=XDA Developers}}</ref> as well as [[ARM64]] versions of [[Windows 10]], [[Windows 11]] and [[Windows Server 2022]], except in Windows Server [[Server Core]] where it is an optional component, and Windows [[Nano Server]] where it is not included. WoW64 aims to take care of many of the differences between 32-bit Windows and 64-bit Windows, particularly involving structural changes to Windows itself.		In [[computing]] on [[Microsoft]] platforms, '''WoW64''' ('''W'''indows 32-bit '''o'''n '''W'''indows '''64'''-bit) is a subsystem of the [[Microsoft Windows\|Windows]] [[operating system]] capable of running [[32-bit]] applications on 64-bit Windows.<ref>{{Cite web \|author1=QuinnRadich \|author2=DCtheGeek \|author3=msatranjr \|date=2020-08-19 \|title=WOW64 Implementation Details \|url=https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|access-date=2023-04-16 \|archive-date=2023-04-16 \|archive-url=https://web.archive.org/web/20230416160609/https://learn.microsoft.com/en-gb/windows/win32/winprog64/wow64-implementation-details \|website=learn.microsoft.com}}</ref> It is included in all [[64-bit]] versions of Windows—including [[Windows XP Professional x64 Edition]], [[IA-64]] and [[x86-64\|x64]] versions of [[Windows Server 2003]], as well as [[x64]] versions of [[Windows Vista]], [[Windows Server 2008]], [[Windows 7]], [[Windows 8]], [[Windows Server 2012]], [[Windows 8.1]], [[Windows 10]], [[Windows Server 2016]], [[Windows Server 2019]], [[Windows 11]], [[Windows Server 2022]], and [[Wine (software)\|Wine]].<ref>{{Cite web \|last=Conway \|first=Adam \|date=2023-01-25 \|title=Wine 8.0 released with better controller compatibility, experimental WoW64 support, and more \|url=https://www.xda-developers.com/wine-80-released/ \|access-date=2023-04-16 \|url-status=live \|archive-url=https://web.archive.org/web/20230416110310/https://www.xda-developers.com/wine-80-released \|archive-date=2023-04-16 \|website=XDA Developers}}</ref> as well as [[ARM64]] versions of [[Windows 10]], [[Windows 11]] and [[Windows Server 2022]], except in Windows Server [[Server Core]] where it is an optional component, and Windows [[Nano Server]] where it is not included. WoW64 aims to take care of many of the differences between 32-bit Windows and 64-bit Windows, particularly involving structural changes to Windows itself.

	==Translation libraries==		==Translation libraries==

Artoria2e5: /* Registry and file system */

2023-05-10T13:05:24Z

Registry and file system

← Previous revision		Revision as of 13:05, 10 May 2023
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	The redirection helps to keep 32-bit applications working without them needing to be aware of the WoW64 status.<ref name=FSR/> If a 32-bit application wants to access the real <code>%SystemRoot%\System32</code>, it can do so through the pseudo-directory <code>%SystemRoot%\sysnative</code> since Windows Vista.<ref name=FSR/> Detection of Wow64 status is possible via {{code\|IsWow64Process()}}.		The redirection helps to keep 32-bit applications working without them needing to be aware of the WoW64 status.<ref name=FSR/> If a 32-bit application wants to access the real <code>%SystemRoot%\System32</code>, it can do so through the pseudo-directory <code>%SystemRoot%\sysnative</code> since Windows Vista.<ref name=FSR/> Detection of Wow64 status is possible via {{code\|IsWow64Process()}}.

	There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes ~~CSIDL~~ {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>		There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>

	==Application compatibility==		==Application compatibility==

Artoria2e5: /* Registry and file system */

2023-05-10T13:04:04Z

Registry and file system

← Previous revision		Revision as of 13:04, 10 May 2023
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	The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.		The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.

	The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are<ref>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>		The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>
	%SystemRoot%\system32\catroot		*%SystemRoot%\system32\catroot
	%SystemRoot%\system32\catroot2		*%SystemRoot%\system32\catroot2
	%SystemRoot%\system32\driverstore (redirected ~~only for~~ Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP)		*%SystemRoot%\system32\driverstore (redirected on Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP)
	%SystemRoot%\system32\drivers\etc		*%SystemRoot%\system32\drivers\etc
	%SystemRoot%\system32\logfiles		*%SystemRoot%\system32\logfiles
	%SystemRoot%\system32\spool		*%SystemRoot%\system32\spool
	32-bit applications are generally not aware that they are running on a 64-bit operating system. 32-bit applications can access <code>%SystemRoot%\System32</code> through the pseudo directory <code>%SystemRoot%\sysnative</code>.<ref>{{cite web \|title=File System Redirector - Win32 apps \|url=https://learn.microsoft.com/en-us/windows/win32/winprog64/file-system-redirector \|website=learn.microsoft.com \|language=en-us}}</ref>

			The redirection helps to keep 32-bit applications working without them needing to be aware of the WoW64 status.<ref name=FSR/> If a 32-bit application wants to access the real <code>%SystemRoot%\System32</code>, it can do so through the pseudo-directory <code>%SystemRoot%\sysnative</code> since Windows Vista.<ref name=FSR/> Detection of Wow64 status is possible via {{code\|IsWow64Process()}}.
⚫	There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called Program Files (x86) to differentiate between the two, while the 64 bit maintains the traditional Program Files name without any additional qualifier.

		⚫	There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called {{tt\|Program Files (x86)}} to differentiate between the two, while the 64 bit maintains the traditional {{tt\|Program Files}} name without any additional qualifier. File system redirection is not used to maintain the separation; instead, WoW64 changes CSIDL {{code\|FOLDERID_ProgramFiles}} and similar query results to point installer programs to the correct directory.<ref>{{cite web \|title=winapi - SHGetFolderPath() 32 bit vs 64 bit \|url=https://stackoverflow.com/a/138473 \|website=Stack Overflow \|language=en}}</ref>

	==Application compatibility==		==Application compatibility==

Artoria2e5: /* Registry and file system */

2023-05-10T12:54:09Z

Registry and file system

← Previous revision		Revision as of 12:54, 10 May 2023
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	The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.		The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.

	The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects ~~32-bit~~ ~~DLLs~~ to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are<ref>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>		The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are<ref>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>
	%SystemRoot%\system32\catroot		%SystemRoot%\system32\catroot
	%SystemRoot%\system32\catroot2		%SystemRoot%\system32\catroot2
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	%SystemRoot%\system32\logfiles		%SystemRoot%\system32\logfiles
	%SystemRoot%\system32\spool		%SystemRoot%\system32\spool
	32-bit applications are generally not aware that they are running on a 64-bit operating system. 32-bit applications can access <code>%SystemRoot%\System32</code> through the pseudo directory <code>%SystemRoot%\sysnative</code>.		32-bit applications are generally not aware that they are running on a 64-bit operating system. 32-bit applications can access <code>%SystemRoot%\System32</code> through the pseudo directory <code>%SystemRoot%\sysnative</code>.<ref>{{cite web \|title=File System Redirector - Win32 apps \|url=https://learn.microsoft.com/en-us/windows/win32/winprog64/file-system-redirector \|website=learn.microsoft.com \|language=en-us}}</ref>

	There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called Program Files (x86) to differentiate between the two, while the 64 bit maintains the traditional Program Files name without any additional qualifier.		There are two [[Program Files]] directories each visible to both 32-bit and 64-bit applications. The directory that stores the 32 bit files is called Program Files (x86) to differentiate between the two, while the 64 bit maintains the traditional Program Files name without any additional qualifier.

← Previous revision		Revision as of 12:44, 26 February 2024
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	# A dll that allows 32-bit x86 instructions to be executed, which varies by [[instruction set architecture]].		# A dll that allows 32-bit x86 instructions to be executed, which varies by [[instruction set architecture]].
	#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>		#* On [[x86-64]], <code>Wow64cpu.dll</code> takes care of switching the processor from 32-bit to 64-bit mode. This is computationally cheap, as x86-64 machines have a native mode for running 32-bit x86 code.<ref>{{cite web \|last1=Eckels \|first1=Stephen \|title=WOW64!Hooks: WOW64 Subsystem Internals and Hooking Techniques \|url=https://www.mandiant.com/resources/blog/wow64-subsystem-internals-and-hooking-techniques \|website=Mandiant \|language=en \|date=November 9, 2020}}</ref>
	#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|~~website=web.~~archive~~.org \|~~date=26 ~~April 2010~~}} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>		#* On [[IA-64]] ([[Itanium 2]]), three files are needed for a slower<ref name="VSdocLAA"/> software emulation: <code>Wow64cpu.dll</code>, a "CPU abstraction layer"; {{code\|IA32Exec.bin}}, the x86 software emulator; and {{code\|Wowia32x.dll}}, the bridge between the emulator and the WOW64 system.<ref>{{cite web \|title=WOW64 Implementation Details (Windows) \|url=http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|date=26 April 2010\|archive-url=https://web.archive.org/web/20100426210819/http://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx \|archive-date=2010-04-26 }} – Earlier version of article, which shows <code>Wow64cpu.dll</code> as part of the IA-64 implementation.</ref>
	#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref name="wow64-dlls"/>		#* On [[ARM_architecture#ARMv8-A\|ARMv8 64-bit]], {{code\|xtajit.dll}} for x86 emulation, and {{code\|wowarmhw.dll}} for switching to ARM32 mode.<ref name="wow64-dlls"/>

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	The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.		The WoW64 subsystem also handles other key aspects of running 32-bit applications. It is involved in managing the interaction of 32-bit applications with the Windows components such as the [[Windows Registry\|Registry]], which has distinct keys for 64-bit and 32-bit applications. For example, HKEY_LOCAL_MACHINE\Software\Wow6432Node is the 32-bit equivalent of HKEY_LOCAL_MACHINE\Software (although 32-bit applications are not aware of this redirection). Some Registry keys are mapped from 64-bit to their 32-bit equivalents, while others have their contents mirrored, depending on the edition of Windows.

	The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com}}</ref>		The operating system uses the <code>[[%SystemRoot%]]\system32</code> directory for its 64-bit library and executable files. This is done for backward compatibility reasons, as many legacy applications are [[hardcoded]] to use that path. When executing 32-bit applications, WoW64 transparently redirects access to "system32" (e.g. DLL loads) to <code>%SystemRoot%\SysWoW64</code>, which contains 32-bit libraries and executables. Exceptions from these redirects are:<ref name=FSR>{{cite web\|url=https://msdn.microsoft.com/en-us/library/aa384187(VS.85)\|title=File System Redirector (Windows)\|website=msdn.microsoft.com\|date=2 February 2023 }}</ref>
	*{{#tag:code\|%SystemRoot%\system32\catroot}}		*{{#tag:code\|%SystemRoot%\system32\catroot}}
	*{{#tag:code\|%SystemRoot%\system32\catroot2}}		*{{#tag:code\|%SystemRoot%\system32\catroot2}}

WoW64 - Revision history

Citation bot: Altered url. URLs might have been anonymized. Add: date, archive-date, archive-url. Removed parameters. | Use this bot. Report bugs. | Suggested by Abductive | Category:Articles to be expanded from June 2021 | #UCB_Category 467/624

Artoria2e5: little wine dll presence note

Artoria2e5: /* Registry and file system */ cite-fixing

Artoria2e5: /* Translation libraries */ huh?

Artoria2e5: Roll /* Architecture */ into /* Translation libraries */

Artoria2e5: OS list too long, just pop in a note instead.

Bender the Bot: /* top */HTTP to HTTPS for Wayback Machine, replaced: http://web.archive.org/ → https://web.archive.org/

Artoria2e5: /* Registry and file system */

Artoria2e5: /* Registry and file system */

Artoria2e5: /* Registry and file system */

Artoria2e5: Roll /* Architecture / into / Translation libraries */