I recently reformatted an old PC after some problems with a different windows install.
I installed the latest driver and CCC for the GPU (Radeon x800 XT PE, sapphire), and while there is improvement from the driver VGA driver and the GPU is detected, the graphics clearly don't work as well as they did with the old windows install, for instance heavier web pages now have low framerate when scrolling, as do embedded videos.
The old OS was XP home, and now it's XP Pro, and some basic functionality wasn't there when I installed pro, I had to download the .NET framework and even the windows installer wizard, so I wonder if this is some configuration problem, or could it be hardware failure?
The drivers stopped officially supporting cards as old as yours after Cat 9.2 i think it was. Anything older than a 2600 i think it is.
You should roll back to an earlier driver. I found 8.12 to be the best of the latest releases.
I tried 9.3 and still have the same problem. It's also 3D though, games that used to run fine now have a worse framerate.
I noticed that my CPU goes to 100% whenever there is any simple animation webpage, as in an ad, and this is where I noticed bad framerate, and as soon as I scroll down to text or image only parts the CPU usage goes down again.