If it came pre-installed I expect it will be OEM, what make and model is it and is there a recovery partition on the laptop so it can be taken back to factory settings or was his CD made when he got the laptop as a one time make for recovery ?
I have no idea where you could get anything online but you'd would have to use the same version as he had installed and that may have included the
drivers that belong to the machine.
Sorry I can't help but maybe one of the experts will be able to give you more information.