ACPI Processor Aggregator Driver (acpipagr) Service Defaults in Windows 8

ACPI Processor Aggregator Device Driver by Microsoft Corporation.

Default Settings

Startup type: Manual
Display name:ACPI Processor Aggregator Driver
Service name:acpipagr
Service type:kernel
Error control:normal
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\acpipagr

Default Behavior

The ACPI Processor Aggregator Driver service is a kernel device driver. In Windows 8 it will not be started until the user starts it. If ACPI Processor Aggregator Driver 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 acpipagr service hasn't been started.

Restore Default Startup Configuration of ACPI Processor Aggregator Driver

1. Run the Command Prompt as an administrator.

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

sc config acpipagr start= demand

3. Close the command window and restart the computer.

The acpipagr service is using the acpipagr.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.