this is with, opera, audio player (aimp), avast av, comodo firewall, utorrent, and ati catalyst running in the background of a computer which has been up for days.
i'm not much of a pc gamer but in the crysis days, i ran it fine in vista x64 albeit with gpu limitation slowdown... more recent games that i tested (alpha protocol, just cause 2) also works fine with no stutter or any noticeable ram hunger.