Need Urgent Help!!!

[PokerProdigy]

So I just downloaded the sng tracker, and then I was trying to turn of my computer it won't turn off. Then I tryed restarting it, and it wouldn't do anything. I am confused and have no clue what is going on or what I need to do about it. I can still get on the internet and stuff like that, it's just that for some reason my computer will not restart or shut down. What should I do?