Hi, recently i momentarily locked my macbook screen as i have always done for the past 8months. when i returned, inserted my usual password it was refused. Now i am locked out of my macbook. the only account that works is the guest which does not require a password. I tried using my os x dvd to reset the password or format my drive but to no avail. the C option does not respond, it still boots to the login screen. However pressing the option key results in a screen with a padlock and an option for some sort of password. I tried all my passwords and still no access.
I was thinking as a last option to remove my hard drive and format it. The only thing is how do i format it with a macbook partition as i don't have access to any apple machine.
I also have a windows partition with bootcamp, but can not access that partition either, as i was already working on the mac side when this problem aroused. I have little snitch installed, don't know if any of these apps are causing this problem.
You can login as a guest and use the Terminal application to add another system admin user from the root using 'sudo' command over and over. But if you're not familiar with Unix, I'd be very careful changing permissions with 'sudo.'
You can probably retrieve your data from the drive if you slave the laptop via firewire to another Macintosh (obviously you'll need to find someone with another Mac).
^^^ Excellent point.
I think you CAN use sudo from a guest account, BUT the system will ask you to provide an admin login to continue. At the very least, op can run 'login' first to try to manually change from the guest account to an admin account.
It seems op remembers his/her password; if something quirky is going on in OSX that blocks the logon (like whatever little snitch does while it monitors the system), using sudo and logging in your admin password, or sudo -s to switch to the root user from the Darwin shell might circumvent that. You could create another admin user where little snitch (if that's the culprit) isn't active. Or you could nip the corrupted software in the butt right from the shell.