Microsoft ACPI Driver Service Defaults in Windows 7

ACPI Driver for NT by Microsoft Corporation.

Default Settings

Startup type:Boot
Display name:Microsoft ACPI Driver
Service name:ACPI
Service type:kernel
Error control:critical
Group:Boot Bus Extender
Path:%SystemRoot%\system32\DRIVERS\ACPI.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ACPI

Default Behavior

Microsoft ACPI Driver is a kernel device driver. In Windows 7 it is being loaded by Boot Loader before Kernel initialization. If Microsoft ACPI Driver fails to load, Windows 7 attempts to write the error data into Event Log and restart the computer, using the Last Known Good configuration. If the Last Known Good configuration is not valid, Windows 7 startup ends with a Stop error. If you remove or disable the ACPI service, Windows 7 won't start.

Restore Default Startup Configuration for Microsoft ACPI Driver

1. Select your Windows 7 edition and service pack, and then click Download.

2. Save the Win7_ACPI_Service_Startup.cmd file to a local storage device.

3. Run the saved file as an administrator.

4. Restart the computer.

The ACPI service is using the ACPI.sys file that is located in the %WinDir%\system32\DRIVERS folder. If the file is changed, damaged or deleted, you can restore its original version from Windows 7 installation media.