With his CD key you will not be allowed to activate it, thus what is the point of installing it, that is if he has already activated his copy, AFAIK. BUt to answer your question:
Run regedit and go to: HKey_Local_MachineSoftwareMicrosoftWindowsNTCurrent VersionWPAEvents, on the right double click on "oobetimer" and it might be located there... I not 100% sure about it though.

It might also be located on the CD itself in the winnt.sif file located in the I386 folder... but I am not 100% sure about that either.

If anyone knows for sure I would be interested in this, if it is not illegal.
BB