This afternoon I turned on my computer (running Windows 7) and it wouldn’t let me log in under my own admin account. It gave me the error “The User Profile Service failed the logon. User profile cannot be loaded.”, therefore not letting me log on. So I Googled from another user account and found the following fix – it worked fine.

Rather than retype the solution see here for help: How to Fix the Error “The User Profile Service failed the logon. User profile cannot be loaded.” and in case it ever disappears PDF here (bits missing).

I’m posting this as much for me as for you in case it ever happens again.