What your friend is referring to is Sysprep, when the system is rebooted it will run through what M$ call the "OOBE or Out of the Box Experience" basically it will be similar to the setup you went through when your laptop was new, I expect your initial setup was branded by the manufacturer.
"Reseal" was an option in the XP/2003 version of sysprep.
I'm assuming you're running 7 as you posted this in the 7 section - Go to Windows > System32 > Sysprep
On the sysprep dialog box select OOBE and check the generalize box - under the shutdown options select > shutdown - It will do its thing and then shut down, all done.