Partition Manager (partmgr) Service Defaults in Windows 8

Disk class filter driver that auctions out partitions to volume managers.

Default Settings

Startup type: Boot
Display name:Partition Manager
Service name:partmgr
Service type:kernel
Error control:critical
Group:Boot Bus Extender
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\partmgr

Default Behavior

The Partition Manager service is a kernel device driver. In Windows 8 it is being loaded by Boot Loader before Kernel initialization. If Partition Manager 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 partmgr service, Windows 8 will fail to start.

Restore Default Startup Configuration of Partition Manager

1. Run the Command Prompt as an administrator.

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

sc config partmgr start= boot
sc start partmgr

3. Close the command window and restart the computer.

The partmgr service is using the partmgr.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.