Disk Defragmenter (defragsvc) Service Defaults in Windows 7

Provides Disk Defragmentation Capabilities.

Default Settings

Startup type: Manual
Display name:Disk Defragmenter
Service name:defragsvc
Service type:own
Error control:normal
Path:%SystemRoot%\system32\svchost.exe -k defragsvc
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\defragsvc
  • SeChangeNotifyPrivilege
  • SeImpersonatePrivilege
  • SeIncreaseWorkingSetPrivilege
  • SeTcbPrivilege
  • SeSystemProfilePrivilege
  • SeAuditPrivilege
  • SeCreateGlobalPrivilege
  • SeBackupPrivilege
  • SeManageVolumePrivilege

Default Behavior

Disk Defragmenter is a Win32 service. In Windows 7 it won't be started if the user doesn't start it. When the Disk Defragmenter service is started, it is running as localSystem in its own process of svchost.exe. If Disk Defragmenter fails to start, Windows 7 attempts to write the failure details into Event Log. Then Windows 7 startup should proceed and the user should be notified that the defragsvc service is not running because of the error.


Disk Defragmenter is unable to start, if the Remote Procedure Call (RPC) service is stopped or disabled.

Restore Default Startup Configuration of Disk Defragmenter

Before you begin doing this, make sure that all the services on which Disk Defragmenter depends are configured by default and function properly. See the list of dependencies above.

1. Run the Command Prompt as an administrator.

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

sc config defragsvc start= demand

3. Close the command window and restart the computer.

The defragsvc service is using the defragsvc.dll file that is located in the C:\Windows\System32 directory. If the file is removed or corrupted, read this article to restore its original version from Windows 7 installation media.