How to reset a forgotten administrator's password in Mac OS X Lion
Reader Lee Benjamin would like to reset his administrator's password but it doesn't work the way it once did. He writes:
I have a MacBook Pro that is used by myself and a few of my family members. My wife and son both know my administrator's password and I think that has created a serious problem. One of my family downloaded a free Solitaire program and left it on my desktop. (It seems that no one remembers doing it.) I went to delete it from my desktop, and, as expected, I was asked to enter my system password. I typed it in but was immediately informed that the entry was incorrect. No one remembers changing the password, but it is definitely not the one I originally created.
In previous operating systems it was possible to insert the installation disc and strip the password entirely. This would allow the user to reset everything quite nicely. Since Lion came from the App store, however, there is no installation disc to insert. Is there some way out of this mess?
Indeed there is. Restart your MacBook Pro with the Option key held down and choose Recovery HD in the startup screen. From the Utilities menu in the Mac OS X Utilities screen that appears, choose Terminal. In the Terminal window that appears enter "resetpassword" (without the quotes) and press Return. A Reset Password window will pop up. Select your startup volume in the top of the window and then, from the pop-up menu below, select a user account—Lee, for example.
In the fields below that enter and confirm your new password. If you like, you can enter a password hint in the appropriate field. When everything is configured to your satisfaction, click on Save. Now choose Restart from the Apple menu and your Mac will do exactly that and will use the new password you've created.