Updated Windows 11 on Parallels: Has been stable since 2021.

Boot loop: Can't system restore. Can't roll back updates. Can't reset PC. Can't even enter safe mode.

All options ran into unexpected errors and cancelled out. Only option left was to shut down or "restart".

Had to clean install and attach the old virtual drive to a new installation to copy files across then copy the new installation's disk back to the old system as a replacement to ensure it was able to activate.

Seriously considering if I even need Windows anymore.