There was a time we users were extremely frustrated because we were unable to install Windows 8.1 using any Windows 8.0 product key. This was a nonsensical decision by Microsoft because Windows 8.1 was a free upgrade to all Windows 8.0 users, and, furthermore, Windows 8.1 could be activated using a Windows 8.0 key. But that same key couldn’t be used to install the OS. One had to obtain a Windows 8.1 key. Fear not, folks. The times have changed, as we can now install Windows 8.1 using our 8.0 product key.
Microsoft has essentially released an updated version of the Windows 8.1 setup that accepts the 8.0 key. If you have an original Windows 8.1 install DVD, I recommend getting the newer version. In order to get the newer version of the setup, please follow the instructions below.
Step 1: Visit the “Create installation media for Windows 8.1” page on the Windows website by clicking here. (URL: http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media)
Step 2: Click on the “Create Media” button, and choose “Run”. You can also click “Save” to have quick access to the tool in the future.
Step 3: When the tool runs, choose your language, edition of Windows, and the architecture. Make sure the option you select matches one for which you have a product key. When you try to install the OS, you will be asked for the key, and if your key doesn’t match the configuration you selected, the OS may not install. In my case, I choose “English (United States” for language”, “Windows 8.1 Pro” for edition, and “64-bit” for architecture.
Step 4: You will be given the option to create a USB media or an ISO. To create an USB media, you will need to plug in a USB Key with at least 4GB of space on it. Warning: all files in the USB will be deleted. If you chose the ISO option, you will be given an image file of the OS which you can later burn to a DVD. You can also run the installer directly from the ISO without burning to a disk. I recommend choosing this option if you want to keep your media for later use. Once you selected an option, click next.
Step 5: If everything goes well, the download will begin. Depending on the speed of your internet, this may take a long time. Once download completes, you will have a fully working installer to reinstall Windows at any time.
Step 6: You either now have a Windows 8.1 ISO or a USB recovery media. If you have an ISO, you may burn it to a DVD and boot from it, or, you may run the setup directly from Windows by mounting the ISO and not having to burn it to a DVD. Either way, when setup asks for the product key, simply type in your Windows 8.0 key, and it should work!
Enjoy, and if you have any questions, let us know!