It does sound like you've got a virus on your computer. When you say that you were getting online popups, do you mean that LW was always popping open & wouldn't stay closed? That's a pretty common one. Please read the thread below
WARNING: Viruses on the network you should be aware of

I'd suggest that you go to Norbiesworld, register & follow the directions for free computer help. Norbie will be able to check out your computer & help you to get rid of any nasties.

Please be careful with what you download. Always make sure that you're using a good AV. Keep it updated & scan all downloaded files before opening!!!