I don't know what is wrong with that - but I can't see an alternative to reinstalling Windows.
You could always try making another Admin account, moving all your stuff to that one and deleting the old account? Worth a try I suppose.
A Knight is sworn to Honour. His heart knows only Virtue. His blade defends the helpless. His might upholds the Weak. His word speaks only truth. His wrath undoes the Wicked.