Help with "Hidden Window"

Please help! When I shutdown or restart my computer, I have to force shutdown of something called "Hidden Window". All references I have found to this say that it is linked to something called "musicmatch jukebox" which I do not have on my computer. Please tell me where else this might come from and is it something that I need to remove? Also, where would I find it to remove it?

ANY help would be greatly appreciated! Thanks in advance!

Ginny

I just wanted to know that have you tried scanning the machine with recommended antiviruses like Microsoft Security Essentials or malwarebytes??? if not then try them out and see if they are helping you to get rid of it or not