It may not have been officially released yet, but there’s still a chance that you have managed to get your hands on a copy of the final RTM version of Windows 8.1. Even if you are planning on waiting, there’s not long to go until the launch date of October 17.
A lot of people will have installed the Preview version of the update to Windows 8 and Microsoft has previously warned that a fresh installation would be needed when the final version was released. The FAQ on Technet forums states that there “is no upgrade path from Windows 8 Consumer Preview or Windows 8 Release Preview to the Released-to-Manufacturing (RTM) version”.
But if you want to upgrade from the Preview release to RTM without having to start from scratch, it can be done quite easily. You’ll need to ensure that you have a copy of WinRAR installed (or some other app that can be used to extract the contents of ISO files) – and this can be downloaded from the program website (there’s a free trial available). For the purposes of this article, we’ll also assume that you have access to an ISO file for Windows 8.1 RTM.
Once WinRAR is installed, right click the ISO file for Windows 8.1 RTM and select the Extract to [folder name] option. Wait for a moment while the disc image is decompressed.
Open up the newly created folder and navigate to the sources folder. Locate the file called cversion.ini and double click it to open it up in Notepad.
You will see two lines of code: MinClient=9458.0 and MinServer=9458.0. You need to change both of the instances of 9458.0 to 9431.0 before closing and saving the file.
Once this is done you can burn the entire folder of file to a DVD, or you can just run it from your hard drive or USB drive. Just double click the setup file in the main folder and you’ll be guided through the installation process.
It won’t take long, and before you know it, you’ll have a copy of Windows 8.1 RTM installed!