For those of you who have been using Windows 7 RC and are now wanting to upgrade to Windows 7 RTM / Final, you will no doubt be faced with the message that you cannot upgrade from the RC to RTM.
However, the workaround available to upgrade from the Beta to the Release Candidate is still applicable here.
So here is what you need to do to upgrade from previous versions of Windows 7 to the RTM / Final;
1. Download the ISO for Windows 7.
2. Extract the ISO to your computer.
3. In the extracted directory there will be a “Sources” directory. Open the file cversion.ini in this folder.
4. Change the MinClient value to 7000.0
Now when you run the setup, you will have the option to Upgrade.
Good luck with your upgrades!