you can set your Virtual memory to whatever you like. All of the above is good advice. As a rule, Virtual Memory settings use available memory, and when that's used up, it uses the Hard Drive. If you set the setting too high, you'll notice the hard drive is almost always in motion. (the missus' PC, which I'm on, only has 64 meg, so I'm hearing the poor HD constantly). So see if you can change your Virtual memory settins, especially if you put in another 256 meg of mem.
There are particular programs (AOHells Instant Mangler, to name just one) that just grab resources all over the place. One thing I do is disable it as soon as I'm booted up (dang kids, but it's cheaper than long distance..;) You can right click and exit the programs. Helps a little. Also clearing out your offline content from the Browser, cleaning unneeded cookies, etc., helps.

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)