So I first dealt with upgrading my laptop from Windows 8.1 to Windows 10. Kept having problems until I downloaded and burned a disc of it from my laptop. After that, all went well. I upgraded, grabbed the license key, and then did a fresh install. Now I just used the same disc I burned for my laptop to upgrade my desktop system from 8.1 to 10. Upgrade went through, but for some reason, my ethernet wouldn't work. Grabbed a USB adapter to connect, and then went through the process of grabbing the license key for that too (since before plugging that in, it showed N/A. Both my systems had different legit license keys when they were running Windows 8.1. Now here's the problem, as mentioned in the title. I check the license key derived from my upgraded desktop, and I come to find that it's the exact same key grabbed from my laptop after it was upgraded. I don't know if it's because I used the same Windows 10 installation disc to upgrade them, but in any case, this should not be, as both had different keys when running Windows 8.1. Was I supposed to download from Microsoft's website again a copy of Windows 10 through my desktop with the tool that generates the ISO? Can I revert back to Windows 8.1 so I can do that (if that's what I needed to do)? Going from 2 separates keys with Windows 8.1 to both having the same key with Windows 10 is not my idea of a good thing, especially if it's not legal for it to be like that. I don't want Microsoft locking me out of my own system because they find two computers running the same key when their own installation made it that way.