Application Compatibility Cache (ahcache) Service Defaults in Windows 8

Cache Compatibility Data and Attributes for Individual PE File.

Default Settings

Startup type:System
Display name:Application Compatibility Cache
Service name:ahcache
Service type:kernel
Error control:normal
Path:%SystemRoot%\system32\DRIVERS\ahcache.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ahcache

Default Behavior

The Application Compatibility Cache service is a kernel device driver. In Windows 8 it is being loaded and initialized at Kernel initialization. If Application Compatibility Cache fails to start, the error details are added to Windows 8 error log. When the operating system startup is complete, the user is being notified that the ahcache service hasn't been started.

Restore Default Startup Configuration for Application Compatibility Cache

1. Run the Command Prompt as an administrator.

2. Copy the commands below, paste them into the command window and press ENTER:

sc config ahcache start= system
sc start ahcache

3. Close the command window and restart the computer.

The ahcache service is using the ahcache.sys file that is located in the %WinDir%\system32\DRIVERS folder. If the file is corrupted or deleted, you can put it back in there.