AVG is 100% free if you validate with an email address if memory serves. I've used it for years and found it to be quite robust. Avast is also quite good, and Avast's pre-Windows boot scan is an added bonus to detect virus components before they have a chance to mask themselves when Windows is up and running.
Daily driver 1: 2007 Jeep Wrangler Unlimited Sport "S"
33" BFG Mud-Terrain KM2s, lots of Rough Country gear - bumper, 2.5" lift, swaybar disconnects, Superwinch 10,000lb winch, Detroit Locker in rear D44 axle, custom exhaust, K+N filtercharger, Superchips-tuned.
Daily driver 2: 2006 Subaru Legacy GT
COBB Stage 1+ package - AccessPort tuner, COBB intake and airbox. Stage 2 coming shortly - COBB 3" AT stainless DP and race cat, custom 3" Magnaflow-based exhaust and Stage 2 COBB tune.
33" BFG Mud-Terrain KM2s, lots of Rough Country gear - bumper, 2.5" lift, swaybar disconnects, Superwinch 10,000lb winch, Detroit Locker in rear D44 axle, custom exhaust, K+N filtercharger, Superchips-tuned.
Daily driver 2: 2006 Subaru Legacy GT
COBB Stage 1+ package - AccessPort tuner, COBB intake and airbox. Stage 2 coming shortly - COBB 3" AT stainless DP and race cat, custom 3" Magnaflow-based exhaust and Stage 2 COBB tune.