There is my instruction of installing Ati driver
for X1950 AGP which I use on nForce3 chipset and athlon X2 3600+:
1. On the Driver list of your graphic card select driver update, find a driver on your computer, choose from the list and there you will se the 2 drivers
: Raden X1950 WDDM and second Standard VGA drive. So select the standard VGA driver which disable the original driver.
2. Download Catalyst driver 8.11 for Windows XP and extract them by interupting the instalation process after extracting.
3. Repeat update procedure up to window where you need specify the folder with extracted XP catalyst driver and then click next. Windows automaticaly update your VGA driver to Radeon X1950.
4. Finally install nForce GART driver (I use nForce 5.11 for Win XP) which improve performance of graphic card.
I don't know if the XP driver working properly but in 3DMark05 and 06 I have the same score as in Windows XP Professional. Also in some 3D games the FPS were very similar.
I think this instruction will be more useful than my english.