Vista background black pleeeease help!!!?

I was experimenting with the firewall rules in vista then my desktop background turned black so I restarted my PC then it asks me for a windows activation code!?! So I say cancel in the bottom right of the window then it loads up my desktop I can still use everything but:

1.My background is still black and in the bottom right of my desktop it says something like Vista not genuine or something the 2006 in white letters

2. This window appears once and a while that says you may be a victim of software counterfeiting

3. When I change my background back 10- 20 minutes later its black again

If someone can tell me how to make my background stay normal but I don't really care if windows is genuine or not but if someone can help me with that, that would be great too i'm pretty sure it has nothing to do with firewall rules but it may be.