If you've Upgraded that Win 8.1 to Win 10, and if this is in the same system.you do not need nor can use your old Win 8.1 license. Simply install Win 10 on the new drive. When it asks for the license key, skip that part and proceed on. It will activate itself when the system goes online later. Windows 8.1 Product Key after Windows 10 Upgrade. I bought a pc with windows 8.1 pre installed. Afterwards i upgraded to windows 10 10240. Now i am going to download the media creation tool for windows 8.1 , to reinstall it. Because i dont have any other option, no rollback and factory reset. This wikiHow teaches you how to find your 25-character Windows 8 product key in a variety of ways. If you can boot into Windows, you can find the key using the command prompt, Windows PowerShell, or a free app called ProduKey. If the PC 2. Enter your product key. Enter the key that you either recovered, received with your Windows purchase, or is affixed to your computer on a sticker. You do not need to type the dashes, as they will be added automatically. Windows will automatically attempt to activate as soon as the key is entered. 3. Go to the Settings > Change PC Settings > Activate Windows > Activate by phone. Step 3. After that, you need to select your location and then click on Next. Step 4. Call the number that is present on the page and follow the voice prompt to complete the activation process. 2. How to Activate Window 8.1 Online. my laptop currently has windows 8.1 single language so I bought a key for windows 8.1 pro but the key is not going through.What windows do I need for the windows 8.1 pro license? Step 2. Click the "System" link. This link opens a new window that shows several properties for your computer including the computer name, network type, CPU and memory capacity, and the product activation key. Once the system is back up and running you can then use the software RWEverything to get the key from the BIOS and activate the version of windows. It is completely legal to setup and deploy an image this way and it is not illegal to use the OEM key After the system has been imaged. + expand. 1. Find your Windows product key with Belarc Advisor. Belarc Advisor is a free program that you download and install on your PC. It doesn't just show your Windows license key, but it also builds a detailed profile of your software and hardware, network inventory, missing Microsoft hotfixes, antivirus status, and security benchmarks. To check Windows 10 activation status, do the following: Open Start > Settings app > Update and Security. Select Activation, in the left panel. Here you will see the activation status. If all has b4Mucq.