All Software on this page is free. You can find all the software you need to remove a virus.

Best free software sites:

http://www.freenew.net
http://www.freeapps.net

Best free anti-spyware and antivirus sites:

http://www.microsoft.com/security_essentials/
http://www.superantispyware.com/
http://free.antivirus.com/hijackthis/
http://www.combofix.org/
http://www.malwarebytes.org/