Ok Bimmy,
This probably means the hardware is not compatible. Before you give up, I assume the card came with its own drivers which should work. May you attach here the .inf file from those drivers? You can get it by running the Setup program, so the package contents are uncompressed in c:\ATI\... then cancel the installation and look for the file inside this folder, it will probably be inside a folder named ...\XP_INF\ or similar. This will provide more information about the particular chipset inside your card.