Win2k

Hi I am trying 2 install ms office 2000 on windows 2000 and I have logged in as administrator, I can install other software no probs, but everytime I try to install MS office 2000 it comes back and says wrong reg # or cd key#, I have another copy of ms office tried it’s reg#, says same thing is ther a switch in win 2000 that is stopping the install ????? has any1 else had this prob ?? How do i get this on customers computer ???