Windows 7 upgrade problem

We have a desktop computer that we had a licenced copy of Windows XP Pro installed on it. I ordered an upgrade copy of Windows 7 Ultimate for the desktop and Windows 7 (Full) Home edition for our laptop. On the desktop I correctly installed Windows 7 64 bit on a new computer disk, clean install, but the licence key I used was from the Win 7 Home edition as they had got mixed up. We were very keen to use it and have installed programs but now when I try to upgrade using the Ultimate licence key it tells me it is in the wrong format. Does anyone have any knowledge of how I can upgrade without losing any of the data and setup?


Essential Member
You don't even need a full copy pf XP. you simply putt in your purchased Windows 7 disk and choose the second option to perform a "clean" install.

No key is rquired unless you have the student versionor an OEM disk

When Windows 7 starts it tells me I have the Home edition installed but I have a licence key for the Ultimate Upgrade edition, the wrong licence key was installed. How do I upgrade from Windows 7 Home edition to Windows 7 Ultimate without losing all of our data?

I had a feeling that this problem was beyond help. Guess I'll have to speak to Microsoft.


Essential Member
Is this a purchased disk,studemt, or OEM

Hi reghakr

Both of these Windows 7 disks are legal store purchased products, not student or OEM.


Essential Member
Did yiu try both versions?

I have tried both the Anytime Upgrade (Invalid Product Key) and booting from the Ultimate Upgrade disk (Cannot Upgrade from Windows 7).


Thank you all above for your help.

I've just sorted it. I found on the Microsoft Forum a Registry Fix and a program run from the command prompt that amongst other things resets the 30 day evaluation counter. Along with the Upgrade disk I have now inserted the product key and had it accepted. I now have Windows 7 Ultimate. Just waiting now to be able to download the MUI language packs and install Virtual XP.


Essential Member
I now about reseting the 39 day limit , but would you mind sharing the registry hack?

Hi reghakr

Open regedit.exe (You can search for it in the start menu) Find this key: HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/MediaBootInstall. Change the value from 1 to 0, and close the registry editor.


Essential Member
Thank you FamilyMan, I appreciate it.


Extraordinary Member
Premium Supporter
I realize that this thread is now over three years old, but perhaps my recent "discovery" will assist somebody needing to reinstall their current Windows installation with the same version. If you just need to reinstall the Windows version that you have due to some files getting lost or corrupted, you can perform an upgrade to the same OS that is currently installed and not lose your user files. This is the same process as upgrading from Windows Vista to Windows 7, for instance, but you are "upgrading" to the same OS version. Note, this does not work, for instance, to upgrade from Home version to Professional version or any other version change. You can only use this procedure to reinstall the exact same version as currently installed and you cannot change your installation key in doing this.

edit: corrected spelling error

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