If it's on your browser only, just reinstalling the browser might work.
If it's some ad-like thing, there's a chance it has some kind of information button or page hidden somewhere if the tabs get opened, sometimes you can just easily turn it off there.
And open up your C://program folder (both normal and the (86) version) and see if there is a new folder in there which doesn't sound familiar. Google the name of the folder. If it's the thing causing it, just delete the whole folder.
Same thing as above with the %appdata folder, you can google how to find it as it's in some folder I'm not sure where and it's normally hidden.
Windows 7 and vista have a function to reset your pc to a sertain time and date. So if you noticed this virus since 2/3/4 days, it might be possible to just go back 1 week in time using this. You won't lose too much, as it's just a short time.
And at last, you can use full factory reset, but it can make your pc slower and you must recover alot of things, which is annoying.