Sounds like you should be fine re-installing XP. Wombat is right about the RAM, the more the better performance with XP. Although I have XP SP3 running on a 300mhz with 128MB RAM. It's just slower, but runs fine.

If you cant find the drivers for your board you can try one of these utilities if you still have the OS running on it.
SysChat - Downloads (Freeware Utilities) - Driver Collector
SysChat - Downloads (Freeware Utilities) - Driver Magician Lite

Also to get all the critical updates for XP on one disc, instaead of hours of downloading them a few at a time, from here.
Offline update from heise security