These are my links to repair MS Windows Virus/Trojan ridden computers, Here are the things I do first. (funny how there are no pages like this for Linux ?!)

      Download and install AdAware and SpyBot Search & Destroy. If your running XP I also recommend Microsoft's Malicious Software Removal Tool As well as reading through Microsoft's Security Web Pages.

      When your computer has been "cleaned", Download and install a "hosts" file. MVPS.org is a good web site that has a hosts file for download and explains exactly what they are.

      Make sure your using a firewall. I prefer to use Microsoft's XP Firewall with AVG Anti Virus. If your running Win98 or Millennium, Then I recommend Zone Alarm

      If all else fails then format the hard drive and consider whether or not you want to reinstall your old insecure, proprietary operating system with the same problems or a secure, stable open source operating system.