Background: I had a desktop PC and a laptop--call it Laptop 1--that both had Win 7 on it. (However, a Win 8.1 disc was included with Laptop 1 because Win 8 had been released already but Dell offered the option of having 7 preinstalled.) Several years ago, I bought a Win 10 Edu license from my university and upgraded Laptop 1 from Win 7 --> Win 10 Edu. I recorded the product key that came with the Win 10 Edu license. Issue now: I bought a new laptop--let's call it Laptop 2--and I want to give Laptop 1 to my mom. With Win 7 EOL, I want to "reclaim" that Win 10 license and install it on my desktop PC. My plan was to downgrade Laptop 1 to Win 8.1 using the disc that was included with Laptop 1. However, I checked the current product key (using this command-prompt method) on Laptop 1, and what I see is completely different from the product key that I recorded at the time of purchase of my Win 10 Edu license. So now I'm confused! How did this happen?? The product key that came with the license I bought--where did it go? Most important question: does this mean that I can just leave this Win 10 installation on Laptop 1 and still use the Win 10 Edu license I bought to upgrade my desktop PC? I'm concerned that somehow there will still be a problem because I'm using the single license to install Win 10 on two computers. Do I have reason to worry?