AVG freeware and Zone alarm freeware here myself,
Been slammed to the point of having to reformat a few hard drives with the best of payware more than a few time in the past, and can't see paying for it anymore unless some one is going to pay me money for my time when the solfware does fail to stop my system from becoming infected in the first place.
Simply backing up is a given, since not, but when you have to nuke the drive(reformat) to kill everything to reload it all when the time comes.