Upgrade Windows 7 Beta to RC version

Today I needed to upgrade my Windows 7 Beta (expires 1 July 2009). After trying to “fool” the setup to believe the Windows 7 Beta to be a Vista (using registry keys) I found some tips regarding a check using cversion.ini in the installation package.

Basically there is a minimum Win7 version to allow upgrade to the Windows 7 RC (7077) but the Beta is build 7000. The trick is simply to change the minimum version to a lower value.

1. Download the ISO file for Windows 7 RC
2. Unpack the ISO file to a directory using for example MagicISO
3. Go to the <Win7RC>\Sources directory
4. Open the cversion.ini file in Notepad
5. Edit the line “MinClient=7077.0” to “MinClient=7000.0”
6. Save the file

Run <Win7RC>\Setup.exe to upgrade your Windows 7 Beta to the RC version. I have sucessfully done this on my computer that now have the following upgrade path (WinXP > WinVista > Vista SP1 > Win7 Beta > Win7RC).

Note! This upgrade path isn’t officially supported by Microsoft and can cause all kinds of problems so I recommend you only to do this test computers (so you don’t have any critical data on the computer if it crasches).