Here am going to share How to Downgrade Windows 7 Ultimate to Professional.Windows 7 Ultimate to Professional without format or data lose. I was thinking it could be straight forward and easy since both are same Operating Systems. But, that was not the scene. Ultimate version is the higher version in Windows 7 and it can’t be downgraded to lower versions officially without formatting or doing a fresh installation. Anyhow, I found a trick to downgrade Windows 7 ultimate to Professional easily without new installation.
Before start the installation just change the two keys in Registry. Its like you are faking the Windows 7 installation that you are using the same version which you are going to install. In my case, I had to change the key to ‘ Windows 7 Professional ’. Make sure you are typing the exact and correct OS version which is written on your installation DVD.
After you change the registry key, insert the Windows 7 Professional installation medium and start.
Make sure you have enough of space in ‘System Partition’ (usually C drive). Allocate enough of time since this will copy your personal data first, downgrade the OS and then copy back your data.
I suggest to clean up (move to different location) your personal data (such as Desktop, My Documents..etc) before start the downgrade for saving time.
..
