In order to get rid of bugs in the system like a virus, first thing is to disable the restore points. Viruses like to hide out in the restore points. If you run a scan and it finds something, it can't get rid of it cause it's getting reinstalled from there. So after disabling the restore points next boot to safe mode and run the scan. In safe mode the virus doesn't load up so it can be knocked out.
If all else fails you can download Stinger and run it. I'll put the link to it at the end of this reply. I strongly suggest you obtain a anti virus program that can run all the time you're online. Not just when you get slapped with a bug.
Now here's the disclaimer> Disabling the restore points will delete them.
Now here's the link to Stinger> http://vil.nai.com/vil/averttools.asp
Good ideas Money_man. Here's another along those lines> www.ccleaner.com
It's called crap cleaner. Turn on all the features and run it.