Back in January Microsoft encrypted all my hard drives without saying anything. I was playing around with a dual boot yesterday and somehow aggravated Secureboot. So my C: panicked and required a 40 character key to unlock.
Your key is backed up to the Microsoft account associated with your install. Which is considerate to the hackers. (and saved me from a re-install) But if you’ve got an unactivated copy, local account, or don’t know your M$ account credentials, your boned.
Control Panel > System Security > Bitlocker Encryption.
BTW, I was aware that M$ was doing this and even made fun of the effected users. Karma.
The Microsoft account holds a backup of the recovery key, which you need to use to restore access in if you do something like significantly change the hardware or move the drive to a different system (which are effectively the same thing).
You don’t need it for day-to-day use of the system, and you can also just get the recovery key and print it out or write it down somewhere.
That’s a good point.
Not as disastrous as I assumed then, thanks!