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.
If you don’t just look at desktop computers, GNU/Linux and Android/Linux are the most used operating systems in the world (not sure which is in the lead).
If you look only at desktop computers, the most used OS is Minix, which is installed on most Intel CPUs and motherbords.