Good security cost money, but lose a valuable information is worse. There is good antivirus and anti-spywares that will help you very good and it not cost a lot. Panda Antivirus 2008 is one of them, is one of the best and trusted antivirus/antispyware in the market. At difference of Norton and Avast it doesn’t need to take a lot of resources to run, at difference of Norton that uses a lot of resources and makes your computer slow.
Another good one is Zone Alarm, antivirus, firewall and antispyware all you need to have the best protection.
I tried AVG the paid version in the store and was a deception I have to give a refund to every person I sold it. The computers were contaminated so easily, was a nightmare. And don’t ask me for the free version. Nothing free works correctly there is no business on it.
I sell Panda in my store $39.00 one year of updates 2 licenses (you can install it in two PCs) If you see is not expensive at all. Zone Alarm is a bit expensive $43.00 but works great. I have reduced considerably the quantity of machines affected with virus.
There is other different antivirus in the market but I recommend one of those I use.