What hardware upgrade to get more performance in my E8400 system?

If you occasionally game, I highly doubt upgrading your graphic card would have any major effect...
And can you explain in which tasks do you feel the computer is slow ?

I think upgrading your OS to 64-bit might be an option...as you can take full advantage of the 4GB RAM and the vRAM available on the graphic card...

A Quad(i7/i5/ ...) can also help speed things up...but that solely depends on the apps you use...

Well I don't really think my computer is slow exactly I guess I was just thinking it could be faster. It does seem to take a long time on bootup until everything is running but that is more of an annoyance than a speed issue. When I rip dvd's or do video work it could use a little increase in power I think. But I have not really done any serious overclocking to unleash the potential of my processor. I need to get a CPU cooler before I do that right now I am running stock. Since I have been out of the hardware loop for a few years since my last build I was figuring there would be a marked increase in performance now but maybe for my limited applications that is not exactly true. Thank you for taking the time to respond I appreciate all comments. I was thinking Windows 7 but since I am running 32 bit right now with windows XP Pro I heard the upgrade was rather painful...I am a bit concerned the 32 bit software I presently own may or may not work in Win 7 which will mean another major layout of cash.

windows 7 is the currently way to go

@donfm try out things like disk cleanup, disk defrag...they might help speed things up a bit...And as for the 64-bit compatablility, better to check out the company website of the apps that you use...