Upgrade Windows 7 Beta Build 7000 to Windows 7 RC Build 7100
Windows 7 RC is out, and the official party line from Redmond is that you won’t be able to upgrade your January build 7000 beta in place (or any build prior to 7077 for that matter). Bill wants you to perform a clean install. Turns out that you CAN upgrade a 7000 install with a few fiddly steps…
The Windows 7 RC (7100) will only allow upgrades from build 7077 upwards. For any older builds, running the upgrade will fail.
I found a writeup on what to do here. I liked it so much I have copied it here (with a few edits). Tudy says to:
1. Download the Windows 7 RC build 7100 .iso.
2. Burn ISO on DVD (or use any ISO file mounting tool, I used MagicISO) and then copy all files and folders to your local hard drive.
3. Now access the “sources” directory within the location where you copied the Windows 7 files & folders.
4. Open the file cversion.ini in your favorite text editor (e.g. Notepad).
5. Change minclient from 7077 to 7000. This value is apparently the build number that the installer checks against. It has to be less than or equal to your build number.
6. Save cversion.ini.
7. Run the installer from the copied directory.
The install process will reboot multiple times during the upgrade process. This is normal. It worked for me, and apparently lots of other people too.