One to watch for is that XP activations, Office etc.. are based on the hardware inside your machine. The code that is generated by the software is created by the contents of your PC. If you phone Microsoft with 2 different request codes for the same Office discs, they could possibly be awkward and refuse to issue a new number. If you reformatted, your hardware stays the same and so would the activation code so there would be no problem. They could also get stroppy about the licence agreement, you son bought a single licence to use office on one PC. Again Microsoft might refuse because of this licencing issue. I am not trying to put a damper on the issue, just pre-warning you that Microsoft could be awkward.