system
2
Welcome to the forums.
This sounds like adware/browser hijack, not a virus per se.
Try Adaware se and Spybot first
http://www.lavasoft.de/support/download/
http://www.safer-networking.org/en/index.html
Post back with the results and some more information about your system so we can help you further. O.S. (Windows version 98 m.e. xp nt etc.)
Also a Hijackthis log would be useful.