PRB: Can't Increase Process Priority

 Last reviewed: December 16, 1996
Article ID: Q110853
The information in this article applies to:
  • Microsoft Win32 Application Programming Interface (API) included with: - Microsoft Windows NT versions 3.5, 4.0

SYMPTOMS

An attempt to increase process priority to the real-time priority REALTIME_PRIORITY_CLASS may not set the PriorityClass to the expected level.

CAUSE

Only accounts with the "Increase Scheduling Priority" permission can increase the priority to real-time. Only Administrators and "Power Users" have this permission by default.

RESOLUTION

Either run the program from an Administrator or Power User account, or grant the Increase Scheduling Priority permission to any user group that must run the program.

STATUS

This behavior is by design.

MORE INFORMATION

The Increase Scheduling Priority permission can be granted by an administrator to a user or group through the User Manager. To do this:

  1. Open the Administrative Tools group in Program Manager.
2. Run the User Manager application. 3. Choose User Rights from the Policies menu. 4. Select the Show Advanced User Rights check box. 5. Select Increase Scheduling Priority from the drop-down list box. 6. Choose the Add button to add users or groups to the list of entities 
   that have this right.
Note that the call to SetPriorityClass() may return success even though the priority was not set to REALTIME_PRIORITY_CLASS, because if you don t have the Increase Scheduling Priority permission, a request for REALTIME_PRIORITY_CLASS is interpreted as a request for the highest priority class allowed in the current account. If it is important to know the actual priority class that was set, use the GetPriorityClass() function.

KBCategory: kbprg kbprb
KBSubcategory: BseProcThrd
Additional reference words: 3.50 4.00 SetPriorityClass GetPriorityClass

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Last reviewed: December 16, 1996
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