Validating windows 7
The GPT GUID can contain brackets, for example: /map:42=.
Multiple /map options can be specified if multiple mappings are required.
Important After the disk has been converted to GPT partition style, the firmware must be reconfigured to boot in UEFI mode.
Make sure that your device supports UEFI before attempting to convert the disk.
Specifies the disk number of the disk to be converted to GPT. The mechanism used is the same as that used by the tool SELECT DISK SYSTEM command.
Either way, there are a couple of different ways to check and make sure that your Windows 7 copy is genuine.It does not pass the "Windows Genuine Advantage" validation.