id say upgrade it if you can if you can find good used parts for it. i had a dell dime 5000 with pent 4 3ghz 512mb ram 80gb HDD and x300 GPU, was good at the time lol, but afterwhile all that became weak trying to multi-task and play games, but due to a virus i brought a laptop instead lol, i did get it sorted short time after, but then it buggered on me, so i sold it few weeks ago as spairs with odd bits missing for £20 ha..
i brought 2gb ram that was meant to fit, but turned out to be wrong, it was a shame there was a mobo issue as i would still have it and have had it upgraded much as it could be, i reckon it have been better than my missus computer she has now(ideq n1).