amy are you running your spy ware check & virus check all the time (daily?). I do mine daily. also reboot now & then . If you do lots of graphics it helps. I now have a gig of ram but still reboot & find things are better right after
MY virus checker runs all the time. I disabled my spam filter because I could get nothing to run.
I need to run the spyware more often than I do but I usually reboot at least once a day. Usually when things slow down to a trickle.