Driver not working properly

I recently replaced a nvidia geforce 2 driver with an ati radeon 9250.The main reason was that i needed a better driver to play splinter cell: pandora tomorrow.I can begin to play the first mission but than the game freezes up.The support help that i have received told me to go into control panel and remove other drivers that are installed because they will interfere with the new one. I am new to this and need some advice. In the control panel it says that i have a nividia windows 2000/xp display driver. Should i delete it and would it help the Radeon to be able to work my new game. All other games etc.. that we have work ok with the new driver. Also i was told to go into the device manager and see if the ati is sharing a number with any of the other devices. I looked and do not see any thing although i am very unsure about this becuase i am not too experienced at troubleshooting. I have windows xp service pack 2, intel pentium 4, 1.6 ghz, 512 mb of ram.

 

Uninstall all NVIDIA Drivers... uninstall Radeon drivers... reset and reinstall newest Radeon drivers.

 

Yeayea yea yea