This might be worthy of a sticky From keznews...... How to Upgrade Windows 7 RC/Beta to Windows 7 RTM 1. Mount Windows 7 RTM Build 7600 ISO and Extract content to any folder or USB drive 2. Now go to Sources folder of Windows 7 and open Ã¢â‚¬Å“cversion.iniÃ¢â‚¬Â file in notepad 3. Modify the Ã¢â‚¬Å“MinClientÃ¢â‚¬Â build number to a value lower than your installed Windows 7 Build. For example, change 7233 to 7000 if you have Windows 7 Beta Build installed. [HostBuild] MinClient=7000.0 MinServer=7100.0 4. Save the updated file to the same location and then run setup.exe to start Windows 7 RC upgrade process. ThatÃ¢â‚¬â„¢s it, Now follow on Screen instructions and choose Upgrade option.