As per the below spec. check with you guys, can i install CAD workstation graphic card? HP Elite 8100Window XPi5 core duo3GB RamHDD 360GB 7200rpm RegardsCy

Yes, but you must make sure that it matches the PCI slot specs. Once you do that I would find a good Quadro or Fire graphics card with as much graphics memory as you can find or afford.  The more graphics memory you can throw at a system running CAD the better.
 
Also, I would think about upgrading to Win 7 and adding more system memory when you can......It will make a big difference.Breeze1042011-12-06 15:38:04

Your system would benefit from an upgrade to a new graphics car.  What do you have now?Is the version of XP you are running 32-bit?  Is that the reason why you show only 3GB of RAM?