Symantec tends to detect a virus after there's nothing it can do about it. Steer clear of Symantec.
I had two businesses last year that used symantec and they both had a virus waltz right through it. Used NOD32 to clean it up.
+1 for NOD32. I've used it for a while and don't plan on switching. It has a small performance footprint and it's stable. It does cost money, but you can find it for free in a dark ally on the internet......
I actually manually uninstalled Norton (which I had a free subscript with through my school) and bought NOD32.