When I wrote the workaround to download the Windows 8.1 ISO from Microsoft was just half of the battle, many users were reporting that they couldn’t get past the first screen because the Windows 8.1 setup wouldn’t take the Windows 8 product key during a clean install.
Short after this issue started popping up, I published a second guide to help users get through the installation, but this involved some online search to hunt down the “Windows 8.1 generic key”, serial number that would only let you continue, but after the installation you had to update your system with the Windows 8 retail product key you paid for.
Now, I found another interesting trick that is documented by Microsoft and it will allow you bypass the product key screen and clean install Windows 8.1 using the ISO without the Windows 8 product key. After the installation and during the Out Of the Box Experience (OOBE), you’ll be prompted again you enter a key and only here is when your Windows 8 key will work, however you can skip this step and do it later.
Let’s dive into the step-by-step instructions.
How to do a clean install of Windows 8.1
Make sure you create a USB bootable drive with the installation files.
Create a Notepad text file and copy the following lines:
[EditionID] Professional [Channel] Retail [VL] 0
In this case because my installation is for Windows 8.1 Pro edition, I’m specifying “Professional” in the EditionID, for the core edition use the EdtionID Core.
Save the text file as ei.cfg inside the SOURCES folder from the bootable drive you just created with the Windows 8.1 installation files.
That’s all! Now try to clean install the OS one more time.
This method will basically allow you to install Windows 8.1 Pro or Core edition as a trial for about 30 days without entering a Windows 8 product key during the installation — because, once again, it won’t work –. But of course you have a valid retail key, so after everything is installed and configured, you can go to PC settings, PC & Devices, PC info, and here you can change and activate your product key.