Before Wednesday, I ran Avira Anti-Vir and Iobit Security 360 for virus and malware protection. I downloaded Microsoft Security Essentials just to give it a shot. I have to say I'm very impressed. Extremely simple GUI, all in one protection, and a low memory footprint. Before I was running about 50-60 mb of RAM in order to support my other antimalware and antivirus. MSE runs at about 15 mb. It scans great, lets my PC start up quick and is overall great. I say give it a try!

http://www.microsoft.com/security_essentials/