Multimedia Class Scheduler - Windows Vista Service
Enables relative prioritization of work based on system-wide task priorities. This is intended mainly for multimedia applications. If this service is stopped, individual tasks resort to their default priority.
This service also exists in Windows 10, 11, 7 and 8.
Startup Type
| Windows Vista edition | without SP | SP1 | SP2 |
|---|---|---|---|
| Starter | Automatic | Automatic | Automatic |
| Home Basic | Automatic | Automatic | Automatic |
| Home Premium | Automatic | Automatic | Automatic |
| Business | Automatic | Automatic | Automatic |
| Ultimate | Automatic | Automatic | Automatic |
Default Properties
| Display name: | Multimedia Class Scheduler |
| Service name: | MMCSS |
| Type: | share |
| Path: | %WinDir%\system32\svchost.exe -k netsvcs |
| File: | %WinDir%\system32\mmcss.dll |
| Error control: | normal |
| Object: | LocalSystem |
| Privileges: |
|
Default Behavior
The Multimedia Class Scheduler service starts as LocalSystem and runs in a shared process of svchost.exe. If Multimedia Class Scheduler fails to start, the error is recorded into the Event Log. Windows Vista startup proceeds, but a message box is displayed informing you that the MMCSS service has failed to start. At least one service depends on Multimedia Class Scheduler. Therefore I do not recommend you to disable it.
Dependencies
If Multimedia Class Scheduler is stopped, the Windows Audio fails to start and initialize.
Restore Default Startup Type of Multimedia Class Scheduler
Automated Restore
1. Select your Windows Vista edition and Service Pack, and then click on the Download button below.
2. Save the RestoreMultimediaClassSchedulerWindowsVista.bat file to any folder on your hard drive.
3. Right-click the downloaded batch file and select Run as administrator.
4. Restart the computer to save changes.
Note. Make sure that the mmcss.dll file exists in the %WinDir%\system32 folder. If this file is missing you can try to restore it from your Windows Vista installation media.