You need to do some homework, I'm afraid. Get yo'sef edumacated!
http://www.symantec.com/avcenter/
http://www.symantec.com/avcenter/faq.html
http://www.symantec.com/avcenter/hoax.html
Or do a search on McAffee. Both Norton and McAffee have good products, but I hear that McAffee gets a little carried away with emailing you once you are on their list.
It's not hard to avoid viruses, if you learn some simple precautions. Since a complete dissertation would be:
- OT for TFL and
- More than I have time for...
I'll leave you with these links and suggest you get busy reading!
BTW, you probably have a Trojan, not a virus. You also need to get edumacated about spyware!