“SYMPTOMS
When you shut down your Microsoft Windows 2000-based computer, you may receive the following access violation error message:

Explorer.EXE - Application Error:
The instruction at “0×00404d51″ referenced memory at “0×00000000″. The memory could not be “read”.
CAUSE
This problem occurs if you have turned on Active Desktop for Windows 2000.
RESOLUTION
Hotfix information
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this hotfix.”