I want now to put a better video card to my TARGA NOW AV 2600 desktop PC
for better graphics now it has (VIA/S3G Unichrome Pro IGP ) 64mb memory type 2
( open GL v 1.2) tell me please which is compatible with my pc
The best graphics card that you can get for your PC is HIS IceQ HD 4670. Keep in mind though, your PC is very old, and it has an outdated AGP slot, for which graphics cards aren't manufactured anymore and the cards that are still in stock (like HD 4670) are overpriced. You could get 5 times (if not more) faster card for the same price if you were to upgrade not only the graphics card. So if you need something better, I'd suggest you build a new PC. You could upgrade your current system for $400, which would blow away the little hd4670 upgrade. Also, not to confuse you, Hd 4670 is WAY WAY WAY more powerful than your current IGP.
Last thing I want to ask you: what will your system be used for?