It is required to enable the option to check the Windows update while doing the installation. Make sure you are typing the exact OS version which is written on your installation DVD.Īfter you changed the registry key, insert the Windows 7 Professional CD/DVD and start the upgrade. In my case, I had to change the key to ‘ Windows 7 Professional ’. Insert the actual Windows 7 Professional CD and start the upgrade.īefore starting the installation, do change two keys in Registry.Better take a backup of the registry before doing any changes). Change registry key and tell Windows that we have the Professional version (Take extra precaution while modifying the registry.Steps to Downgrade Windows 7 Ultimate to Professional Anyhow, I found a trick to downgrade Windows 7 ultimate to Professional easily without the new installation.
The Ultimate version is the higher version of Windows 7 and it can’t be downgraded to lower versions officially without formatting and doing a fresh installation. The following method is to fake the Windows OS and trick that we have the Professional version installed, then do an upgrade. Even though both are the same Windows 7 family, it is not easy to switch the versions especially backwards. I installed/downgraded Windows 7 Ultimate to the Professional version without formatting or reinstalling OS on one of the computers.