Handle leaks may occur in AELookupSvc (Application Experience Lookup Service) on Windows Server 2003 with SP1 (Service Pack 1) when multiple processes are created at the same time.
AELookupSvc creates a work item to perform a compatibility check for every new process. When the number of work items in the queue exceeds the number of worker threads that process work items, new worker threads are created. These new worker threads do not close their handles when they exit, causing handle leaks.
NOTE: AELookupSvc caches new processes to prevent an unnecessary compatibility check the next time that process or program starts. Some executable files, like CMD.EXE never get cached. For more information about the Application Experience Lookup Service, see tip 9749 » Description of the Application Experience Lookup Service in Windows Server 2003 SP1.