Due to my setting Secure Boot mode in my BIOS to "Windows" rather than "Other OS," Windows encrypted both my boot drive and my RAID without my asking, and it broke the "Windows Activation," too. I could not switch Secure Boot back to "Other OS" without losing access to my hard disks. "Turn off BitLocker" on the RAID drive has been running for a couple of hours so far, with no indication of when it will finish.