My friend has this card on a Gigabyte K8N, XP Pro 32bit. We updated it from an X800 last month or so, no problems at all, got the driver off ATIs site.

He updated the driver through CCC this past week, and has been getting this error ever since.

Google returns quite a few hits but none of the suggestions in them have worked.

We have tried:
Uninstalling MS .NET FX 3.5, then 3.0
Driver Cleaner in regular and safe mode
Uninstalling and reinstalling the Nvidia chipset drivers (accidentally, he saw Nvidia in the list and nuked em, so we put them back on, no change)
Modifying an INF file per instructions found on a forum
Sapphire's drivers
The driver we used when we installed the card last month, the .exe is still on his desktop.
Uninstalling it in Device Manager and scanning for H/W changes to find it again.
Using XP's driver wizard and manually pointing it at the appropriate file (CX77271.INF IIRC)

Weird:
The card is automatically disabled (red X) in Device Manager on every boot EXCEPT after we ran DC in safe mode. That time it only had a warning (yellow triangle and !)

He fixed this with a system restore. I'll add more details for googlers if I get them.

Edit to add:
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