Windows 7 Validation

OEM stands for Original Equipment Manufacturer.

Say there's a computer shop down the street called: Nibiru's Warp Drive Computers.

I would be the OEM since I custom-build the systems for the end-user and therefore product support is supplied by me, not MS.

OEM basically means it is to be used for a specific manufacturers hardware and THEY (example DELL) must provide the support, MS does not offer support to OEM versions.

So if I buy the boxed OEM version 64bit, I can use it to replace the key without reinstall?

Yes, that is correct. Plus you'll have the disc in case you ever need to reinstall it.

You'll just enter the new key in the: Computer / Properties window at the bottom where it says: Change Product Key under the Windows Activation section of the window.

Please see this stress reducing video.

YouTube- I'm about to whip somebodys ass