At 5 years you are at the point of where most of this stuff has failed. Fixing a working machine is not a good idea, even more so a machine that is 2 generations back of the pack.
Enjoy the machine. Don't drop a dime on it.
I have a dell PWS360 with Pentium 4 CPU 1GP Ram, Nvidia Quadro FX 500/600 video. Running Windows XP pro. Had since 2004. works very well, have had NO problems not self induced. Would like to improve performance if possible.
? Should I add more ram? upgrade video card? do both? or look at newer system?
Any advice would be appreciated.
TKS

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic