For anyone that is interested.
Most new pc's/laptops that come with a copy of windows 7 have a SLIC 2.1 table (vista had a SLIC 2.0). It is in the bios and holds the key for windows 7.
When you install a OEM copy of windows, it checks the bios for the SLIC table and if it matches the OEM certificate on your installation DVD/USB stick it automatically activates windows.
You can only install language packs for windows 7 ultimate or enterprise. So if you buy a laptop here, with windows 7 pro/home in spanish on it, thats all you can have.
For mikes laptop i just took my HP DVD, copied over the Lenovo OEM certificate which matches his SLIC table and created him a bootable USB stick (his laptop doesnt have a DVD drive). So it now looks exactly like a copy of Windows 7 as if he purchased it in the states.