Apart from the fact that the original install disc would more than probable have been an OEM copy, possibly with a lot of features normally included in the purchased copy omitted replacing the bought copy with the supplied one shold present no issues but recalling back this one came up a while ago, small local company I supplied with new units and full install discs of XP pro for seven replacement machines asked MS if it could de-register it's currnet copies of XP home it had purchased by mistake and had been running, was told flatly NO, by Redmond.
However there IT tech sold em on when it was noticed that while the copies could not be re-registered under another owner, MS was quite happy to re-activate the copies to any machine once installed using their automated 'Telephone' activation service, His view was that how many times would the actual owners name/address be asked for in any dealings with MS by the average home user, not often enough to worry about as the help service component had already expired and would not be acted upon by MS even if the new owner tried to use the service.
I have no comment on the legality of this action though except...
