I've had instances before in XP, when the device-driver is supported via an out-of-the-box driver, and if you go to Device Manager, and instead of "roll back" (which you cannot do unless you've installed a new driver "on top"), you select "Uninstall" - well, XP will dutifully go and do that, and also delete the actual drivers and INF used, clean off of the HD. Simplest way to get those drivers back appears to be an overtop complete OS repair installation. Wasn't able to get the device to install just by pointing Device Manager to the installation CD, didn't feel like manually extracting out all of the files onto the HD just to let it search through them.
I'm guessing that XP did things this way, intentionally, in contrast to how W2K behaves: if you Uninstall a device, the INF is still left around, and will attempt to auto-install again on the next boot, but then may be missing the .SYS driver or whatever, and causes more issues.