Can not connect to internet/ trojen

Hey all. OK my buddy has a HP that got a Trojan. Now he has avg free ver and it said that it was cleaned. I also ran spybot and that's coming up with nothing. It was a Trojan that wanted him to buy some anti virus crap. So now he can not connect to the Internet in any way,shape or form.



I tried a system restore and it says there are no restore points and I also tried to restore from the factory image and that was a no go. The last one I was able to do when he first got the computer. He also does not have any disk's that comes with it. He is running vista 64 bit.

Any help would be great.