... keys work . What can be the problem ?
It sounds like to me you might have a virus or a virus damaged some of your files.
I use Eset Node32 Antivirus free online scanner - it works better than anything I have every used. They also have a free 30 day trial and the best part is they don't trick or force you into buying it before they will clean your pc - they fix everything they find right out of the gate =) Just google Eset free online scanner and you will find the direct link!