HELP! I can't make any changes on my MBP Lion 10.7.1 ; Keeps asking for password prom

[withinthemind]

Hello,
I've recently installed Mac Os X Lion, then I installed boot camp and rEFIt and NTFS driver for mac. Now, whenever I boot on Mas OS X and I try to install something or change a setting, it asks for my admin password like it always did. The problem is that, after I enter my password, the dialog dissapears, but the installation doesn't move further. When I click next, the password prompt REAPPEARS and so on. I cannot create another use account because it also asks me for my password and it's the same issue. It's like my system is "locked" and I cannot edit any important file or setting.

I've searched on google to no avail. Anyone has suggestions?

THANKS!

 

[alexreich]

reboot your Mac and hold Command+S as it starts (hold before white screen)

Once you get a prompt, type:

mount /usr/bin -uw [return]
passwd (your username)
type new password for account
type again to confirm
exit (to boot into OS)

That should change the password to your account if I recall correctly. It has been a while since hacking into my school's admin accounts.

EDIT 1: If you type everything from above, but replace (username) with a non-existent account, the account will be created on your Machine. You could create an account that way.