Microsoft has released the Microsoft Windows Malicious Software Removal Tool to help remove specific, prevalent malicious software from computers that are running Microsoft Windows Server 2003, Microsoft Windows XP, or Microsoft Windows 2000.
The Malicious Software Removal Tool supersedes all virus-cleaner tools that were previously released by Microsoft. You can download the Malicious Software Removal Tool from the Microsoft Download Center. You can also run an online version of the tool from the Malicious Software Removal Tool Web site on Microsoft.com. To run the Malicious Software Removal Tool from either location, you must log on to your computer with an account that is a member of the Administrators group. If you are running Windows XP, you can also run the Malicious Software Removal Tool from the Windows Update Web site or by using Automatic Updates.
To run the tool:
http://www.microsoft.com/security/malwareremove/default.mspx