You may need updated drivers compatible with XP(SP2) from the manufacturer.
You can try the following so XP can recognize your video card.
Shutdown the PC and unplug the monitor. Then open the case and
remove the videocard, it has one screw to remove where the monitor plugs in.
Reboot the PC (with the case still open). Wait about 20 seconds for it
cannot boot without a monitor. Turn off the power. Reinsert the video card
and plug the monitor in. Reboot and XP's "plug&play" feature should come up
with a notice that it is installing the video card and/or ask you to insert
the video card installation disk. Then just following the prompts. If your
PC has an on-board video card
to the motherboard, it's a different ballgame. The card may be defective or
need
updated drivers compatible with XP(SP2).
Good luck :~)