I'm hoping that someone can help with me this as Microsoft doesn't seem willing. I have a several year old (>5) computer that I built and originally had Windows XP on. I later, maybe 3 years ago, installed Windows 7. Since then, the computer became unstable, randomly rebooting (no blue screen or anything, just reboots). Initially, this would only happen after several days of being on, but now happens within a few hours of booting up, something just minutes (It seems to happen when it's try to access secondary drives, but that's not the problem I'm asking about). I read on some message board that this was likely from a known incompatibility between the motherboard and Windows 7. So, when the preview release of Window 10 was available, I downloaded it and installed it. It didn't fix the random reboot problem, but I followed through updating preview builds. (I think I did 2 or 3 of the preview builds.) When the release build of Windows 10 became available. I immediately tried to install it. The preview builds didn't seem to have any trouble activating. I tried the Windows Update way to upgrade to the release build, but it would stick a few minutes into the upgrade process and the revert back to the previous version. I then downloaded the Windows 10 .iso and burned it to a DVD. I installed from that DVD and was able to do the upgrade. It didn't have a product key, though, but I didn't think that was necessary because when I would do the the preview build installations, I would skip the product key and it would activate a few minutes after the installation completed anyway. Around the same time, I removed one of the 2 monitors that I was using on this computer to use on another computer that I have. The computer in question has 2 video cards that can be set up in CrossFire. Since I now only had 1 monitor, I set the 2 cards to crossfire for the single remaining monitor. I mention this, because I don't know if maybe this caused a change in the hardware profile from my device. Windows 10 has never activated since installing the release build. I did an online chat with Microsoft support and they kept asking for my product key. I can't find my Windows 7 disc for the key and it, of course, isn't on the box because I installed it myself. They tried something to query a product key on my system, but it doesn't return anything because it's not activating because it doesn't have a key. The are 3 windows.old directories on the computer that were made during the various updates/upgrades that I did attempting to get Windows 10 to activate (I had tried reverting to the previous system during the original window period and then reinstalling, but it wouldn't revert, so I reinstalled one of the preview versions from a DVD that I still had to try to update again to the release build, but that didn't work. So, I reinstalled the release version from the DVD at boot, again). The folders are windows.old, windows.old.001, and windows.old.002. I found a utility that said that it could retrieve the product key from a windows.old directory. It needed to look in a file called "SOFTWARE". Only windows.old.002 had this file, The other 2 folders only seemed to contain user directories and not the windows/system folder. That utility returned the generic product key for the Windows 10 preview build that I had last used. I brought the 2nd monitor back and returned the hardware to the state that it was when I was running Windows 7, but that hasn't made it activate. Does anyone have any other suggestions. I've bought a newer motherboard and CPU that I'm hoping will not have the random reboot problem, but I'm afraid to install them because I would think that would erase any chance of Windows 10 activating based on the hardware profile and I'll have to actually pay for it. The prospects of finding my Windows 7 installation media are kind of slim at this point. Thanks.