Hi I'm planning on upgrading my motherboard and cpu. I'm going from an celeron cpu to an AMD athalon XP processor. I was wondering if I would need to reinstall windows after I make this upgrade, since I'm keeping my old harddrive?
Yes backup because most likely it won't, but you may get lucky! IT's better to fresh install anyhow that way all the drivers for the new board, etc load well and don't conflict with the "old" stuff! Try it anyhow and see, if not you have your backup disks all ready; just format and refresh!
IMHO, It does not matter if you can or can't. Just Delete the partition, create a new partition, format & reinstall your OS. This will be the best thing you can do for long term stability. Also if your PSU is not 350+ watts, upgrade it with a new Enermax or Antec 350 or more watt PSU. Good Luck
god knows your entire system setup & he would answer your questions if he could just stop laughing