I wanted to give people a heads up about a 'little' issue I ran into re: Windows 10.
To start at the beginning, I built the first incarnation of my HTPC in 2009 just after the release of Windows 7. I bought a copy at full retail price in late-2009 and installed it on the HTPC. Over the course of running Windows 7 I made a few hardware upgrades that sometimes required me calling into MS to 'transfer' my product key to my new hardware. A few years ago I bought a Windows 8.1 upgrade through my employer at the time to move the HTPC from Win7 to Win8.1. Over the last few years I also performed a few hardware upgrades, some of of which required me to call MS to transfer my product key to my new hardware.
On July 29th I upgraded the currently running Win8.1 installation to Win10. Hurray! Everything went smoothly. However, last week we had a terrible electrical storm run through our area and my computer got zapped. I don't know if it was an electrical surge or static electricity that built up in the air. It may have just been a bad coincidence. Regardless, I tested all of the HTPC components individually in my desktop machine and came to the conclusion that the only component that was truly fried was the motherboard. I bought a replacement online and this weekend had the opportunity to install it. I boot up the computer and find that Windows has deactivated itself. "No problem, I've seen this before," I tell myself. The interesting thing is that usually when my Windows installation had deactivated itself due to hardware changes in the past, it would prompt me with a number to call to reactivate as if my product key could see that it was installed on different hardware and was willing to be transferred over, if necessary. Well, I didn't get that prompt this time so I did some searching online to get the MS number to call.
Eventually I found one, called them up, and they told me that the Win10 licenses are no longer transferable, even if the old hardware has been decommissioned. Since Win10 no longer tracks product keys, it relies on the old versions of Windows to transfer product keys and then activate the upgrade to Win10. Essentially, my retail copy of Win8.1 had been turned into an OEM copy of Win10 upon upgrading.
So here I was stuck. The only way to install Windows 10 again is to completely wipe my drive (which has been in continuous use for 6 years, never had to wipe it before), install Win8.1 (that I don't own any install media for, since the download link I bought for the upgrade disc expired years ago), enter my Win8.1 product key, call MS to have them transfer it to my new hardware, and then redownload and reinstall Win10 via the same upgrade path I just did a month ago.
Screw them. Seriously. This is the way that software licensing is headed: you don't own your Windows OS any more, just like our farmers don't own their John Deere tractors. And at least in my case I still had the 'opportunity' to waste an entire weekend reinstalling 2 OSes and setting up all of my HTPC and server program settings again. What happens in a year when you can no longer secure the 'free upgrade?' I honestly don't know, but if the current methodology is still the case then MS is simply trying to get you 'hooked' on Win10. As soon as you replace your motherboard or something else that requires reactivation, you'll have to wipe your installation and go back to Win8.1. Your Win10 activation is dependent on the hash stored on their servers that is calculated from your system configuration. That hash doesn't exist for your new hardware so you'll have to buy Win10 to continue to use it.
I went the sane route of course and illegally activated my Win10 installation via one of the 4 or 5 tools available in the shadier part of the internet. If MS wants to come after me for illegally activating a 'free' upgrade that effectively overwrites two products I've already bought retail copies of (and have the product keys to prove it), then nothing would make me happier.