Microsoft said that Internet Explorer 7 has been causing some errors with the Active Desktop, if you have Internet Explorer 7 on your computer read this article for the solution to fix the problem.
This could also be caused by a corrupt user profile.
To locate the list of local user profiles, right-click My Computer, click Properties, and then click Settings on the Advanced tab under User Profile.
You might need to create a new user profile, and copy your data to it.
See this Microsoft Article for instructions on how to do that:
If that doesn’t work, you could try doing a repair Install of the operating system (and install all windows updates after that).