When you installed your copy of WindowsXP (or since you've installed it), did you do anything to modify it? This problem has come up in the past with people that have either had a corrupted file (which the fix I've recommended already resolves) or have customized their Windows install. By removing certain components, your system will run faster, but it may lose functionality for any programs that require those certain components.
-Mike
[Stardock Support]