When I build a new PC, I could not transfer my old 7 pro retail license, even though it worked fine on my old PC running Windows 10 and it even said it was a digital license connected to my MS account.

So I bought a Win 10 pro key from one of the ebay resellers aber everything was fine... until it wasn't. I updated the firmware for my mainboard and Windows took that for a replacement of hardware. Troubleshooter did not show three option "I recently changed my hardware" and did not give me the option to call Microsoft's support.

Turns out it was a "one time install" key which was invalidated by changing the hardware. So it couldn't activate a second time. And since the key seller was out of business at that time (they'll change accounts every few months), I had no way of getting the key replaced.

Luckily, I still had an old Windows 7 COA with key and CD lying around from an old Dell business Workstation. That activated just fine.

But yeah, even if you have a valid license connected to your Microsoft account, there's no way of seeing it in your account, and it's not guaranteed MS will honor it.

One thing I just recently learned - NewPipe can cast to Kodi, but it needs a bit of setup.

First, you're going to need kodi running somewhere (FireTV Stick, Android TV, ...) and (currently) update the YouTube Addon to the latest Alpha.

(I installed it via the following repo: http://ftp.fau.de/osmc/osmc/download/dev/anxdpanic/repositories/repository.yt.testing_unofficial-2.0.5.zip )

Also, you'll need kore or yatse installed on your phone / tablet.

Then you'll need to allow remote control in the kodi settings for the app you just installed...

And lastly you'll have to go to the NewPipe settings (Audio/Video) and toggle "show >play with kodi<".

So... It's quite a bit of work. But I guess if you're using NewPipe, you're not adverse to some fiddling.