Upgrade Windows 7 from beta to RC (bulid 7000 to 7100)

Microsoft has bulit a detection method into Windows 7 RC install files so that it detects OS other than Windows Vista and prevents the upgrade. This will likely be a major problem for enthusiasts who had installed Windows 7 beta and want to upgrade to the release candidate.

The official explanation is that upgrading from beta software builds to RC is blocked to avoid problems during such an upgrade. Microsoft recommends a fresh install of Windows 7 RC for the same reason. For example, Windows 7 beta builds like 7077 are blocked from being upgraded to Windows 7 (build 7100) RC.

However, there is a known hack to skip the version detection and upgrade from beta to RC. This method of hacking involves modifying a .ini file within the ISO file before starting the installer. Follow the instructions below for the hack.

Hack to upgrade Windows 7 beta to RC directly

1. If you do not have it already, download the Windows 7 setup file.


2. Extract the content of the ISO file to a folder using IZArc.


3. Inside that folder, open the sources directory.


4. Open cversion.ini in Notepad or similar text editor.


5. Change the 4-digit number after the word MinClient build number to a lower value. For our purposes, change it from 7100 to 7000.


6. Save the file (make sure to save, NOT save as).


7. Start up the Windows 7 installation.