In about 2012 I bought a pre-built Dell PC, the origin of my current PC build. It had Windows 8 installed and activated on it, which then was upgraded to 8.1 when that came out. I had done 2 groups of upgrades to the PC, all while keeping that install, and Windows would say I need a key. I would then proceed to call up Microsoft and they would ask me how many PC's this copy of Windows was on, and I'd say one of course, and they'd give me a key to type into the box and all was well. Then we have 2015 where I upgrade to Windows 10 and clone the install afterwards to an SSD after my second set of upgrades to the system. All is working well, no need to put the key in again. Here we are in 2016 and I just created a boot media for Windows 10 and installed it clean after a 3rd set of upgrades to the system, and I have the little watermark saying to activate Windows. Problem is, I don't have the key and I never did have one as Windows came preinstalled on the Dell. I don't see any sort of number I can call and get this sorted out and I'd rather not buy something I already have the rights to. I need a way to get the old key back or get a new one from Microsoft. Any help is appreciated.