If you are unable to successfully log in after two boots, you get booted into a password recovery mode that has options including "My keyboard works but I am un

If you are unable to successfully log in after two boots, you get booted into a password recovery mode that has options including "My keyboard works but I am unable to enter my password", and on the reset options, makes mention of being careful about the characters you choose... ... so a bit more commonplace than "defective unit" or "admin software".