Microsoft ACPIEx Driver Service Defaults in Windows 8

ACPIEx Driver by Microsoft Corporation.

Default Settings

Startup type: Boot
Display name:Microsoft ACPIEx Driver
Service name:acpiex
Service type:kernel
Error control:critical
Group:Boot Bus Extender
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\acpiex

Default Behavior

The Microsoft ACPIEx Driver service is a kernel device driver. In Windows 8 it is being loaded by Boot Loader before Kernel initialization. If Microsoft ACPIEx Driver fails to load or initialize, the error details should be automatically logged. Then Windows 8 is restarting the PC and attempting to use the Last Known Good configuration. If the Last Known Good configuration isn't working properly, Windows 8 startup ends with a Stop error. If you disable the acpiex service, Windows 8 will fail to start.


All the services listed below will not start if Microsoft ACPIEx Driver is disabled:

Restore Default Startup Configuration of Microsoft ACPIEx Driver

1. Run the Command Prompt as an administrator.

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

sc config acpiex start= boot
sc start acpiex

3. Close the command window and restart the computer.

The acpiex service is using the acpiex.sys file that is located in the C:\Windows\System32\Drivers directory. If the file is removed or corrupted, read this article to restore its original version from Windows 8 installation media.