My brand new MacBook finally returned from AppleCare today, almost a month after it stopped working (I’m not entirely sure the delay is Apple’s fault, actually — in retrospect I have trouble trusting an affiliate who has a $60 “express” option to get your computer checked within the week). It’s back with a new motherboard (sorry, I meant logic board) and, for some reason, a nice message at the login window: “You are unable to log in to the user account ‘admin’ at this time.”

So, what to do then? Put the OS X install CD in the drive, restart the computer while pressing’ C’, and go to Utilities / Reset Password to reset the password for your FileVault account. I have no idea what went wrong, not to mention how a logic board exchange caused that, but all it took was resetting the password to what it already was supposed to be. (It took a bit of trial and error for me, though, because the install CD booted in Qwerty and I typed my password in Azerty, assuming that an Apple install was intelligent enough to figure what layout my keyboard has.)

Moral of the story: enabling FileVault for the admin account is a bad idea.