First of all, I’d like to congratulate Microsoft for (finally) signing off the RTM. Since it will soon be available for download and many users running the RC (Release Candidate) plan to install it, the following question arises:
Is it possible to upgrade from the RC to the RTM (Release to Manufacturing)?
According to Microsoft, upgrading from the RC (or any previous build) is not supported as mentioned in the “Windows 7 Upgrade Paths” document:
Unsupported Upgrade Scenarios
…Pre-release in-place upgrades across milestones (for example, Windows 7 RC to Windows 7 RTM) are not supported.
This isn’t good news for everyone, particularly those who have been using the RC for a while, customized it and changed its settings. However, there’s a workaround in the Windows 7 RTM installation to upgrade from the RC.
Workaround to Upgrade from RC to RTM
- Extract the files in the ISO
- Browse to the “sources” directory
- Open “cversion.ini”
- Change the ‘MinClient’ number from “7233.0” to “7100.0”
- You should end up with something like this:
- Save the file
- Run “setup.exe” from the extrated files and upgrade!
The upgrade should also work with Windows 7 builds less than 7100 if the ‘MinClient’ is set to number lower than build number installed. Although it works, performing a clean install of Windows 7 is still recommended. (Use at your own risk…)