k, im just gonna go out on a limb here and assume that your board is AMD... have you installed teh latest 4in1 drivers (if its VIA).. do you have the sp1 installed for you xp ?
You could always try booting into windows safe mode (Im not sure about Xp cause im used to Win2k does it have safe mode?), uninstall the drivers.. then reinstall them ?
Other than that I wouldn't have a clue .. if worst comes to worst.. you could always reformat and reinstall windows