You may have this issue if you downloaded a copy of Windows 7 or if someone else installed it for you.
Either way, there are a couple of different ways to check and make sure that your Windows 7 copy is genuine.
So, in conclusion, if you have bought a copy of Windows 7 from a shady local computer dealer or off e Bay for a reduced price, you may want to check and make sure the product key is actually valid and not counterfeit!
Offline conversion of system disks with earlier versions of Windows installed, such as Windows 7, 8, or 8.1 are not officially supported.
The recommended method to convert these disks is to upgrade the operating system to Windows 10 first, then perform the MBR to GPT conversion.
It does not pass the "Windows Genuine Advantage" validation.
I suspect my os is being used by one or more others.
Specifies additional partition type mappings between MBR and GPT.