Originally Posted by zzpulp
Playing CSS, you probably will not need more than 2 GB on XP. However, as Dave said, memory is cheap enough so that you could upgrade anyway. Maybe you should just do all your most intensive apps one day and then use task manager (performance tab) to check your peak commit charge. The peak commit charge is the maximum memory at any given time ever requested to the OS (however it resets on reboots).