Downgrade windows 7 to any minor version

You can easy migrate to a minor version of windows 7 just with few easy steps:
First of all you have to change these two registry keys and after that you can install minor version of Windows 7

 Example:

Your registry:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"EditionID"="Ultimate"
"ProductName"="Windows 7 Ultimate"

for installing Windows 7 Home Premium:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"EditionID"="HOMEPREMIUM"
"ProductName"="Windows 7 HOMEPREMIUM"

for installing Windows 7 Professional:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"EditionID"="Professional"
"ProductName"="Windows 7 Professional"

The version name to be entered must be identical to the version name on the installation DVD. There is differences of an English and a German installation, so be careful!

For downgrading do not boot from Windows 7 installation DVD. You have to start up your windows 7 as usual and then insert your minor version into DVD drive and click update

The upgrade is processing background so you can easily do your job till everything is done.

NB!
The entire process usually takes about an hour, but it could be much longer if you frequently use the My Documents or Program Files folders. When in doubt, let the installer run a little longer, and be sure to leave non-essential USB devices disconnected.


After upgrade is finish you will see welcome screen

All data, documents, music and movie files, installed driver and programs, shortcuts and user settings are retained. Only in a few Windows 7 programs some settings are reset to the initial settings; e.g. in the "services".
After upgrade you have to reactivate your copy of windows 7.