woftam, I just love your registration date!
Why Free? If you're serious about protecting your PC and Data from virus attacks, why do you think you are going to get something really useful for free? You need to update the virus database at least every week and you must have something that will not conflict with your operating system and other applications. Someone, somewhere, has to do this for you and is not likely to be doing it for the fun of it.
The proprietary anti-virus programs are cheap and reliable and the updates take account of new viruses almost as soon as they are written. So it is really false economy to be cheapskate over this essential protection. My most frequent activity is sorting out PCs that won't fuction properly as the result of virus attacks.
I use McAfee and it's pretty good. I think it's about $30US for the current version 5. There are other good ones, too, and I'm surprised that Norton doesn't please you. Once you've been bitten, you'll never begrudge that amount again.