windows xp shutdown

I recently upgraded my motherboard from a FIC az11e to an ecs k7s5a with ddr. I had windows xp home edition on it before and when I did the hardware upgrade I reformatted and reloaded xp. After putting in the last driver (intel hardware modem) the computer would not shut down completely. This modem worked with xp on the other motherboard. I put in the xp drivers that came with it as well as the new ones from the intel website. No help. If I uninstall the modem before shutdown it will completelyshutdown.