Windows AppCompat Database Registry Path
This article provides an overview of where Windows stores the
configuration for system-wide Application Compatibility (AppCompat)
database files within the Windows Registry. You will learn the exact
registry path used to manage these database references
(.sdb files), understand the key entries associated with
them, and see how the operating system utilizes this data to maintain
application compatibility.
The System-Wide AppCompat Registry Path
In the Windows Registry Editor (regedit.exe), the
configuration and registration for system-wide application compatibility
database files are located at:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\InstalledSDBFor 32-bit applications running on 64-bit systems, Windows may also reference:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\InstalledSDBStructure of the InstalledSDB Key
Under the InstalledSDB key, Windows organizes registered
compatibility databases by their unique Globally Unique Identifier
(GUID). Each subkey represents an individual .sdb file
deployed to the system (such as the default system database or custom
databases deployed via enterprise tools like
sdbinst.exe).
Common values found within each GUID subkey include:
- DatabasePath: The full file system path to the
.sdbfile (for system databases, typically located inC:\Windows\AppPatch\orC:\Windows\AppPatch\Custom\). - DatabaseType: A DWORD indicating the category and origin of the database (e.g., system vs. custom).
- DatabaseDescription: A string providing the human-readable name of the database.
Related Compatibility Registry Keys
Beyond InstalledSDB, other subkeys under
AppCompatFlags manage specific compatibility behaviors:
AppCompatFlags\Layers: Stores compatibility mode settings (e.g., “Run as Administrator” or “Windows 7 Compatibility Mode”) applied globally across applications.AppCompatFlags\Custom: Contains references to custom compatibility fixes (shims) applied to specific executables.