How to downgrade the win7 flagship version system

Win7 system can be upgraded from a low version to a high version, which I believe many people know. So can you downgrade from the high version to the final version? What I know seems to be downgraded from the win7 flagship version to the home premium version.
1
Open the registry
Click Start, type regedit in the search box, press Enter.
2
Target: HKEY_LOCAL_MACHINESoftwareMicrosoftWindows NTCurrentVersion
Then modify the value of "EditionID" on the right side to "HomePremium", and then modify the value of "ProductName" to "Windows 7 HomePremium", let the installation The program assumes that the current system is a lower version (note that the modified registry value name here must match the system name on your installation disk) and then reinstall it with the original installation CD (requires reactivation).
3
For this method, I feel like I didn't say it, I still need to use the system disk.
So if you want to downgrade, just go to the next version you want and change it.
4
If you don't know where to go, you want the system.
Then you can go to www.355189.com, the system home to download.
The above is about the computer skills of egg pain. How to downgrade the win7 flagship version system. Why is it that the egg hurts, because I feel useless, just simply share it. Let people who really need it be able to use it.