how to DOWNGRADE windows 7 version

i see this question being asked a lot in the last couple days around the net. so here is the solution for you.

okay so you have either the beta or rc installed. or maybe you got ultimate off a torrent etc and you decided to buy premium instead due to whatever reason maybe cost etc....and you dont want to format. YES you can do a in place DOWNGRADE or go from rc release to retail. its very easy to do.

lets in this example say you have ultimate installed and want professional.

what you do is simple. Create a registry file by opening notepad and saving it as a .reg file i call mine upgrade.reg this will contain (everything below except the < and >)the following:
<
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"CurrentBuild"="7100"
"EditionID"="Professional"
"CurrentBuildNumber"="7100"
>

run this. reboot and now insert the Professional disk if you are using professional and run setup from WITHIN windows. Do an upgrade. done.

works the same for any version just modify the reg file to include the version you want. so instead of professional you would enter home premium where i listed professional. and if you are using the ultimate rc and want to go to the retail one simply put Ultimate in the reg file instead of professional, otherwise keep exactly as i have it. etc..i have done this MANY TIMES and can assure you it works.