Radeon X300/550 driver issues.

  I recently decided to upgrade the drivers for my ATI Radeon X300/550 (came with my Dimension 4700 model) after experiencing some choppiness playing a game.  I decided to download the most recent drivers directly from the AMD/ATI support website as I have done successfully countless times before.  I'm running WinXP Home SP 2, so I downloaded the corresponding drivers for both the X550 model and the X300.  I don't remember ever having to choose between the two before, but I figured one had to work. 

  So I uninstall all ATI software on my machine as recommended by the ATI install guide, and run the driver install; only to be greeted with an error message:

"setup did not find a driver compatible with your current hardware or operating system.  setup will now exit." 

  This leaves me in a bit of a dilemma, without drivers new or old.  Since then I have tried XP drivers from the ATI site for both model numbers, including old versions, and even found an ancient set provided by the Dell website for series-specific card models.  Nothing works.

   I've been wrestling with ATI support for the last few days, but their automated responses really aren't all that helpful.  Is there anybody who has been in a similar situation, or who might have a suggestion as to how I could resolve this?

In case it helps I saved a DirectX log with my specs, though without drivers my system won't tell me much about the video card.

Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.070227-2254)

System Model: Dimension 4700  

Processor: Intel(R) Pentium(R) 4 CPU 2.80GHz (2 CPUs)

Memory: 510MB RAM 

Display 

Name    RADEON X300/X550 Series
PNP Device ID    PCI\VEN_1002&DEV_5B60&SUBSYS_03021002&REV_00\4&166AB6CD&0&0008