How To Upgrade Windows 7 Beta and RC to RTM

You have a preview of Windows 7 and want to run the RTM version now it is finished. The only problem is that Microsoft wont let you. Windows 7 can upgrade but the have disabled it by default.

This is primarily to encourage fresh installs instead of upgrades from the betas as well as Vista. But if you want to upgrade it is a simple file edit that will do it.

Instructions

• Download the RTM of Windows 7 or Buy it
• Mount it using Daemontools or Extract using a zip tool
• Copy the files to a folder on your hard drive
• Go to \sources\cversion.ini in your newly created folder
• Change the MinClient number to something smaller than the build you are on try 6900

• Save the file and run the setup.exe from the copied files
• follow the install routine and select Upgrade

• Windows 7 Will reboot 2-3 times and should take 1-2 hours
• BACKUP first, I didn’t loose any data but you might!