My laptop has got a virus today

its a sony vaio, windows 7, i cant use the internet browser on that account, it redirects me to another site, which insists on buying the anti virus softe ware.
I am on a different account, on the same laptop now.
Please help me get rid of the virus?
Edited by Pandy, 27 August 2010 - 06:30 PM.
Moved from Malware logs as no logs are posted and the prep guide not followed ~Pandy