Re: bit defender
bitdefender is awful, the detection is ok but nothing special. the RAM usage and bloat is the same if not worse than norton or mcafee. I don't recommend it because it slows down web browsing and is extremely slow.
Desktop: Dell Dimension E510, 2.5GB RAM, Intel P4 3.0GHZ, 250GB HDD, Windows Vista Premium. Might not be the best, but the old girl is still running good.