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Registry Keys Affected by Windows Installations That Include Windows on Windows (WOW) Support For Multiple Processor Architectures

  • Article
  • 03/25/2022

In 64-bit Windows installations beginning with Windows XP and Windows Server 2003, and in 32-bit ARM processor architecture Windows installations beginning with Windows RT (Windows 8) (hereafter referenced as affected Windows installations), certain registry keys are redirected.

On affected Windows installations, when a process with a processor architecture different from the operating system's processor architecture (referred to hereafter as a WOW application) makes a registry call for a redirected key, the registry redirector intercepts the call and maps it to the key's corresponding physical registry location. For example, a 32-bit Intel IA-32 [x86] application running on an AMD64 / Intel x86-x64 Windows installation would be affected by a redirected registry key; when this x86 application calls a redirected key, the registry redirector intercepts the application's call and redirects it to the key's corresponding physical registry location. For more information, see Registry Redirector.

Other registry keys are shared by applications of differing processor architectures on affected Windows installations. WOW application registry calls to shared keys are not redirected. Instead, one physical copy of the key is mapped into each logical view of the registry.

Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP: A subset of redirected registry keys are also reflected to keep the keys and their values synchronized between 32-bit and 64-bit views of the registry. Registry reflection was removed starting with Windows 7 and Windows Server 2008 R2. For more information, see Registry Reflection.

This topic lists registry keys that are redirected, shared, or redirected and reflected under WOW. It also lists symbolic links that provide compatibility for existing applications that may use hardcoded registry key paths containing Wow6432Node, the redirected registry location for x86 processes running on AMD64 Windows installations. For more information, see the following:

Redirected, Shared, and Reflected Keys Under WOW

For WOW applications on affected Windows installations, the following table lists registry keys that are redirected, shared, or redirected and reflected. Subkeys of the keys in this table inherit the parent key's behavior unless otherwise specified. If a key has no parent listed in this table, the key is shared.

Key Windows Server 2008 R2, Windows 7, and Newer Windows Server 2008, Windows Vista, Windows Server 2003, and Windows XP
HKEY_LOCAL_MACHINE Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE Redirected Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Classes Shared Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Appid Shared Redirected and reflected with one exception: the DllSurrogate and DllSurrogateExecutable registry values are not reflected if their value is an empty string.
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID Redirected Redirected and reflected only for CLSIDs that do not specify InprocServer32 or InprocHandler32.
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\DirectShow Redirected Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\HCP Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface Redirected Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Media Type Redirected Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\MediaFoundation Redirected Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Clients Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3 Shared Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Calais\Current Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Calais\Readers Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Services Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\CTF\SystemShared Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\CTF\TIP Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DFS Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Driver Signing Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\EnterpriseCertificates Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\EventSystem Shared Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSMQ Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Non-Driver Signing Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Notepad\DefaultFonts Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\OLE Shared Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RAS Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RPC Shared Redirected and reflected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SOFTWARE\Microsoft\Shared Tools\MSInfo Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\TermServLicensing Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\TransactionServer Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Control Panel\Cursors\Schemes Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AutoplayHandlers Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\DriveIcons Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\KindMap Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Telephony\Locations Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontDpi Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontLink Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontMapper Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Gre_Initialize Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Language Pack Shared Redirected
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Ports Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Print Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\Policies Shared Shared
HKEY_LOCAL_MACHINE\SOFTWARE\RegisteredApplications Shared Shared; Windows Server 2003 and Windows XP: This key was added in Windows Vista.
HKEY_CURRENT_USER Shared Shared
HKEY_CURRENT_USER\SOFTWARE Shared Shared
HKEY_CURRENT_USER\SOFTWARE\Classes Shared Redirected and reflected
HKEY_CURRENT_USER\SOFTWARE\Classes\Appid Shared Redirected and reflected with one exception: the DllSurrogate and DllSurrogateExecutable registry values are not reflected if their value is an empty string.
HKEY_CURRENT_USER\SOFTWARE\Classes\CLSID Redirected Redirected and reflected
HKEY_CURRENT_USER\SOFTWARE\Classes\DirectShow Redirected Redirected and reflected
HKEY_CURRENT_USER\SOFTWARE\Classes\Interface Redirected Redirected and reflected
HKEY_CURRENT_USER\SOFTWARE\Classes\Media Type Redirected Redirected and reflected
HKEY_CURRENT_USER\SOFTWARE\Classes\MediaFoundation Redirected Redirected and reflected

HKEY_CURRENT_USER is a symbolic link to HKEY_USERS\[SID] where [SID] indicates a match for the current user's security ID (SID). HKEY_USERS\[SID]\SOFTWARE\Classes is a symbolic link to HKEY_USERS\[SID]_Classes.

HKEY_CLASSES_ROOT is a merged view of HKEY_LOCAL_MACHINE\SOFTWARE\Classes and HKEY_CURRENT_USER\SOFTWARE\Classes. Redirected keys in these registry paths are effectively redirected for HKEY_CLASSES_ROOT also. This is also true for reflected keys on systems that support them.

WOW64 defines the following symbolic links only for compatibility with existing applications that may use hardcoded registry key paths containing Wow6432Node. New applications should avoid using Wow6432Node in registry key paths.

  • HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes is linked to HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node
  • HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node\AppId is linked to HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppId
  • HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node\PROTOCOLS is linked to HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PROTOCOLS
  • HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node\Typelib is linked to HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Typelib

Windows Server 2008, Windows Vista, Windows Server 2003, and Windows XP: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes is linked to HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node. Other symbolic links were added in Windows 7 and Windows Server 2008 R2.

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