i use 256 and it works just fine
all u have to do is power off all those system services things that windows loads by defult or get added there later
there are ways to tweek your comp to get the best of your ram
or theres always linux
wich does mirricles with even 192 mbs of ram and a 800 mhz proccesor
i play half life on it
but then again i once got it to run on 96 mbs of ram
not online but on a local server