How do I delete a previous admin on osx 10.4?

May 4, 2007 12:40 PM

I bought a used macbook (osx 10.4.8). The previous owner is still set as the admin. I cannot add another account without their password. Putting in the install disks also requires a password. How can I delete the previous user and create a new account for myself?
posted by LavishingUndertone to computers & internet (16 comments total)

Do you want to save any of what's on the drive?
posted by jjg at 12:48 PM on May 4, 2007

jjg:
There's nothing on the drive that I need.
posted by LavishingUndertone at 12:51 PM on May 4, 2007

Boot from the install disks (insert the OS X CD/DVD, hold down "C" while it reboots) then follow these instructions.
posted by buxtonbluecat at 12:51 PM on May 4, 2007 [1 favorite]

If you have an installation CD (DVD?), you can boot off it, there's an option to reset the password.

Othwerwise, boot the machine into single user mode. You get a root prompt, and then you can change passwords and do other emergency administrative stuff.
posted by phliar at 12:51 PM on May 4, 2007

buxtonbluecat:
When I put them in holding down "c" it still prompted me for the password.
posted by LavishingUndertone at 12:52 PM on May 4, 2007

I should have mentioned, on the page I linked to, scroll down to "Resetting the original administrator account password."
posted by buxtonbluecat at 12:53 PM on May 4, 2007

put the install disk in, shut down machine. start it up while holding the C key down. This will cause it to boot off the CD. Now you can erase and install for fresh new mac goodness.

(or if you are feeling nosey, reset the password (in menu when booted from cd, utilities-reset password) now you can log in as the admin and see what goodies they had on there.
posted by ShawnString at 12:54 PM on May 4, 2007

When I put them in holding down "c" it still prompted me for the password.

Did it appear to boot from the CD/DVD? Did the installer start? See what ShawString said - put in CD; restart; hold down "C" while machine reboots

If this doesn't work, and you're still being asked for a password, it is possible the previous owner set an Open Firmware password, in which case, see here for how to reset it.
posted by buxtonbluecat at 1:00 PM on May 4, 2007

If you have access to another Mac and a FireWire cable, I believe you could use that second Mac to erase the HD, then reinstall with the disks you have:

Connect the two Macs via FireWire. Boot your MacBook while holding down the "T" key. It will appear as an external disk on the Mac. Then, use Disk Utility to erase it. Eject the MacBook "disk", and boot it off your install disks.

Or, call the previous owner and get his password...
posted by gazole at 1:02 PM on May 4, 2007

Aha, I'd forgotten about the "holding down C" trick. That would be a quicker solution, for sure, assuming it works. You do have to hold it down for what seems like an hour.
posted by gazole at 1:03 PM on May 4, 2007

Sounds like there is an EFI (aka Open Firmware) password set. In which case you will be unable to boot to CD/DVD, target disc mode, bootable network server, etc.

It is possible to reset/remove that password but all of us who know how are sworn to secrecy by the threat of apple taking all our pennies and killing our loved ones.

I was unable to find the answer via google so it seems this might actually be a well-kept secret. You might just want to do like gazole suggested and ask the previous owner to either tell you the EFI password or make arrangements to remove it for you. At that point you will be able to follow the other directions here and boot to the OSX DVD and use the Reset Password utility to change the admin & root passwords. Or just do a clean install...
posted by J-Garr at 2:20 PM on May 4, 2007

Just to clarify ...

It will be useful for the people here if you can describe what the password prompt looks like. An Open Firmware password should look very old-style tech, if memory serves -- like a command-line prompt from the '80s or '90s. A normal Macintosh password prompt should look like Apple's normal GUI.

If you're getting the old-style tech password prompt, then follow the Open Firmware reset directions buxtonbluecat linked to (namely, removing and replacing some of the RAM and then zapping the PRAM three times); if you're getting the Apple GUI, then you're not holding down the 'C' at the proper time in the bootup.
posted by WCityMike at 2:47 PM on May 4, 2007

It turns out that is incorrect. A MacBook doesn't use OpenFirmware, so procedures relating to it do not apply.
posted by majick at 4:01 PM on May 4, 2007

If all attempts at changing the password fail, create a DBAN CD and wipe the hard drive. Then you can reinstall from scratch. (You don't need to do a high security wipe though, anything that will clear the MBR will be enough to get it to let you install over the old data.) Note that this won't work if it's an Open Firmware password.
posted by philomathoholic at 4:06 PM on May 4, 2007

majick, you are correct that macbooks don't use Open Firmware. However they do have EFI (Extensible Firmware Interface) and an EFI password which can be enabled. For the purposes of this question the EFI password and Open Firmware password can be considered the same thing.
posted by J-Garr at 4:25 PM on May 4, 2007

I will reiterate, since perhaps it was not clear when stated in the manner I used: procedures relating to [Open Firmware] do not apply. Functionally, EFI is indeed equivalent to OF in many ways, including password protection of booting from removable media. In implementation, it is not similar.
posted by majick at 6:47 PM on May 4, 2007