Many people have installed the beta or release candidate releases of Windows 7. Now that Windows 7 RTM is out they want to upgrade these installations. They will found out that it is not possible. The installer will complain that you have in stalled a version of Windows 7 that cannot be upgraded. It that it? Must you do a clean install and loose all the stuff from the other installs? No, see the steps underneath to upgrade the per-RTM Windows 7 installations.

How to Upgrade Windows 7 RC/Beta to Windows 7 RTM

1. Mount Windows 7 RTM Build 7600 ISO and Extract content to any folder or USB drive.
2. Now go to Sources folder of Windows 7 and open “cversion.ini” file in notepad.
3. Modify the “MinClient” build number to a value lower than your installed Windows 7 Build. For example, change 7233 to 7000 if you have Windows 7 Beta Build installed.

[HostBuild]
MinClient=7000.0
MinServer=7100.0

4. Save the updated file to the same location and then run setup.exe to start Windows 7 RC upgrade process.

That’s it, Now follow on Screen instructions and choose Upgrade option.