You have a Microsoft .NET Framework 2.0 Service Pack 2 (SP2)-based application or a Microsoft .NET Framework 3.5 Service Pack 1 (SP1)-based application that uses the WindowsIdentity class. When you dispose of the WindowsIdentity object, instances of the SafeTokenHandle object and SafeLocalAllocHandle object that were created by the WindowsIdentity object are queued incorrectly for finalization.
If you use the !finalizequeue command in WinDbg, you see that there is an increase in the finalization queue length. When the finalization queue length grows large, performance decreases.
This problem occurs because the Dispose methods of the SafeTokenHandle object and the SafeLocalAllocHandle object do not call the GC.SuppressFinalize method.
Hotfix Replacement Information
The hotfix that corresponds to KB967615 has been superseded with the hotfix KB981574, which contains all fixes that were previously included in KB967615. You should use the hotfix KB981574 to fix the issues described in KB967615. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
981574 The splash screen stays open longer than usual when you try to start Excel on a computer that has the .NET Framework 3.5 SP1 installed
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.