I have Norton on my downstairs PC and AVG on my own PC, and tbh I prefer AVG - runs in the backround better, is faster and don't slow the PC down as much. Still does real time scanning and all that stuff.....

You can get the "pay" version, but Grisoft offer a decent freebie version - don't ask me why, I don't know why any of these companies do stuff fro free but I am glad they do