Update Windows 7 Beta to Release Candidate

The Microsoft Engineering team has outlined how Windows 7 Beta users can upgrade their version of Windows 7 to the soon to be released Release Candidate of Windows 7. The disappointing news is that Microsoft suggests to do a clean install instead as the development changes introduced after the release of the beta of Windows 7 were not always compatible with the upgrades made thereafter. 

A clean install on the other hand would mean that all the changes and customizations made to the operating system by the user would be lost. This is a nuisance although everyone knew beforehand that this could happen eventually. Microsoft is suggesting to do a clean install or upgrade from Windows Vista to Windows 7.

The RC, however, is about getting breadth coverage to validate the product in real-world scenarios. As a result, we want to encourage you to revert to a Vista image and upgrade or to do a clean install, rather than upgrade the existing Beta.

The Windows 7 release candidate setup will quit automatically if it recognizes a pre-RC build on the computer system. Microsoft did however publish a workaround for that for users who really need to do it:

1. Download the ISO as you did previously and burn the ISO to a DVD.
2. Copy the whole image to a storage location you wish to run the upgrade from (a bootable flash drive or a directory on any partition on the machine running the pre-release build).
3. Browse to the sources directory.
4. Open the file cversion.ini in a text editor like Notepad.
5. Modify the MinClient build number to a value lower than the down-level build. For example, change 7100 to 7000 (pictured below).
6. Save the file in place with the same name.
7. Run setup like you would normally from this modified copy of the image and the version check will be bypassed.