help what do xp product code lost

need help my computer just locked up tryed to reinstall windows xp pro got to the user code screan cant find it was on disk holder but not now is ther anything to do short of going and buying new xp disk please need computer for work and it wont do anything

 

If it's an OEM machine there should be a sticker on the case with product key.

 

Call microsoft and explain. They will probably have you enter a long code and when you get in just use a keyfinder to get the product key for a later install. I messed up and put the same XP on two machines I did have two CD's and just told them what I did. It is an 800 number and it only takes a few minutes. Just have the machine running so you can enter the number.