Today I was tasked with upgrading some Windows 7 Home Premium PCs to Windows 7 Ultimate.
For some reason the installer will not let you upgrade from Home premium to Ultimate and it tries to force you to do a clean install.
I managed to find a way around this by editing some registry keys.
Open Regedit and navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion
And change:
EditionID from HomePremium to Enterprise
and
ProductName from Windows 7 HomePremium to Enterprise
Then re run your upgrade and everything should run as you expected!
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