I'm using McAfee and mine expires shortly. Kevy (and other LoTers) have pointed me to
AVG free. I like it, and I am actually not going to renew McAfee and go with the full $50 pay version of AVG. For one thing, when it scans my PC, it does not slow it down, which is a good thing.
Oh, the only downside to the free version of AVG is that it does scan your PC every day, you can't schedule it to scan weekly. It's not a big deal, I merely cancel the scan. It updates daily and runs great.