Only account is a locked "Guest" after upgrading to OS Lion My friend updated his 13" MacBook Pro to OS X Lion today. After upgrading he has been met with a login screen showing a single account, "Guest". This "Guest" account is password-protected and none of the existing passwords he used on the computer seem to work.

My friend had previously installed rEFIt on his computer, which apparently hasn't been updated for Lion yet.

I found this thread on MacRumors where a few other people are reporting the same problem.

Does anyone know of a solution?
An easier way is to:


Get a terminal/console somehow (e.g. start up in recovery mode by holding down option).
Delete the file /Volumes/&lt;your root volume&gt;/Library/Preferences/com.apple.loginwindow.plist.
Reboot.


That's it.