Windows 7 RC1

Got hold of the RC1 of Win7 today and thought I would upgrade my 3 machines running the beta to RC1. I assumed this would be an upgrade but that didn't work and I got:

"You can’t upgrade this prerelease version of Windows 7. Go online to see how to install Windows 7 and keep your files and settings."

This is the solution from Microsft's Blog...http://blogs.msdn.com/e7/archive/2009/04/07/delivering-a-quality-upgrade-experience.aspx

Here’s what you can do to bypass the check for pre-release upgrade IF YOU REALLY REALLY NEED TO:

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
   
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.