Yep I checked your techy specs,
Expansion Bus
Bus types
PCI and AGP
Bus speed
PCI: 33 MHz; AGP: 66 MHz
AGP connector
one
AGP connector size
172 pins
AGP connector data width (maximum)
32 bits
AGP bus protocols
4x/2x modes at 1.5 V
PCI connectors
four
PCI connector size
120 pins
PCI connector data width
(maximum)
32 bits
It has an AGP 4x slot which is an older 1.5v type system. You're going to be very limited in the video card choices unfortunately, as most are AGP 8x cards these days. Also any card you find to work, will be a very low end unit and not worth investing in, to be all honest with you. :(
AGP card info link
Based on that info, the spare Fx5200 card I have wouldn't even work as there would be voltage issues.
It's time to cut back on soda and chips M8 and get a new Dell!
Check out the XPS-410 or 710 models.. they kick ass..