If you have any Bitcoins, they are no longer welcome by Microsoft for payment of digital content for Windows 10 and Windows 10 Mobile. The company has quietly removed the option of adding Bitcoins to Microsoft accounts for those two operating platforms.
"You can no longer redeem Bitcoin into your Microsoft account. Existing balances in your account will still be available for purchases from Microsoft Store, but can't be refunded."
Microsoft started accepting Bitcoins in Microsoft account back in December 2014. Once in the account, they could be used to buy digital content from the Windows Store for things like apps, games and in-app purchases, along with the Xbox Store for games and other content.
At the moment, this change appears only to affect Windows 10 PC and Mobile users, since the option to redeem Bitcoin to a Microsoft account via other means is apparently still live.