Here is a Complex one :-\
Not anymore!
OK I DO NOT recommend you Remove explorer and Replace it with the one on the CD Because it can cause SYSTEM ERRORS.
What I think you should do is Find out if its a FAKE explorer.
Usually in Task Manager, Go to Processes and END An explorer with the Lowest CPU Memory Usage (usually there is 2 one the real 1 the other is a Fake)
And IF you BY Mistake screw you’re self up, Open Task Manager (Ctrl+Alt+Delete) And Press New Task.
Type Explorer and well That should fix about it!
Hope this helps!
Pika