This is the Windows XP forum so your question about Windows Vista is out of place here.

Try the Windows Vista forum.

Before you do, try the advice in Grif's post in the link below;
http://forums.cnet.com/5208-6122_102-0.html?messageID=2969621#2969621

No need to use any other computer to download those utilities if you are still able to download and install software on this system. But run, update, then scan with those utilities one at a time, to check there is no other malware on the system.

Mark