Recently, I went to the ATI website and then I downloaded the ATI Catalyst thing for my Radeon X300. When I looked up in the instructions, it said I had to uninstall the current ATI Control Panel first and then restart the PC. And so I did. But when it restarted and finished showing that windows XP loading screen, it just went blank and showed "Cannot display this video mode" in black and white. I was baffled by this I tried the Dell Resource CD and I run the option for the Graphics thing. It showed "PASS" but I still had the same problem when I restarted the PC. Can anyone please help me?

PS. My PC is a Dell Dimension 4700 (I think it matters for some reason)