Domain Controllers enter infinite boot loops

Happy New Year from Microsoft! The January 2022 Patch Tuesday update sent Active Directory Domain Controllers into endless reboot loops. LSASS.exe — the process responsible for authentication in every Windows domain — would crash with error 0xc0000005, taking the entire server down with it and restarting every few minutes. Hyper-V was also broken for good measure. This affected the backbone of virtually every enterprise Windows network. Microsoft pulled the updates and rushed out emergency fixes a week later, but not before IT departments worldwide had a very exciting start to the year.