The Windows 7 Release Candidate will be released to the world on May 5th and the many millions of beta testers will definitely want to download and use it; however upgrading straight from the beta to the RC won’t be easy.
Microsoft would prefer that you go back to Vista and then upgrade to Windows 7 RC, that way will give them the correct metrics to analyse the upgrade process. That’s fair enough but it’s a bit of a hassle doing that so there is a way to get from A to B without going via Vista:
Here’s what you can do to bypass the check for pre-release upgrade IF YOU REALLY REALLY NEED TO:
- Download the ISO as you did previously and burn the ISO to a DVD.
- 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).
- Browse to the sources directory.
- Open the file cversion.ini in a text editor like Notepad.
- Modify the MinClient build number to a value lower than the down-level build. For example, change 7100 to 7000 (pictured below).
- Save the file in place with the same name.
- Run setup like you would normally from this modified copy of the image and the version check will be bypassed.
See more over @ the Engineering Windows 7 blog here.