What is a good free full protection virus protection ?

[Sanguas]

For free antivirus, Microsoft Security Essentials is actually pretty darn good. For paid antivirus, I've used ESET NOD32 Antivirus with many of my clients and it seems to work great. None of them have gotten viruses, ever. It takes up very little resources and doesn't have huge annoying popups that tell you every little unimportant thing that happens on your computer. It just simply updates and watches out for viruses. They also have a suite that includes a firewall, spam blocker, etc. It's their Smart Security line. If you go to http://www.facebook.com/corebiztech they are giving away a copy of the Smart Security 4 (upgradeable to version 5) for free in a contest. Just like them and enter for free. Wouldn't hurt.

You can always check http://www.virusbtn.com. They are a company that routinely tests all antivirus software and rate them. ESET always makes the "VB100" list. There are also many other good virus scanners out there with high detection rates, but high detection rates aren't everything. Look at reviews and make sure the scanners aren't resource hogs or have very few options. You want a well balanced scanner that's quick, configurable, out of sight, and hard for viruses to shut down and deploy their nasty code.