I lost my admin user (Mac OS X 10.5)

I lost my admin user (Mac OS X 10.5)

If you are unfortunate enough to delete your only admin user, or remove his admin capability, then as long as you have another user with login capability, you can give that user admin rights as shown below. You can then re-create the original user or reinstate the admin capability using the Accounts Pane in System Preferences.

Print this post out in a mono-spaced font, and type carefully, paying attention to spaces and punctuation, since you cannot copy/paste in Single User mode. Note that everything is case-sensitive.

Caution: in single user mode you have root privileges. Be careful! Substitute the short name of "youruser" below.

Boot into single user mode (Command-S) at startup which will eventually get you a shell prompt (ending in #). Then type the following:

fsck -fy

Repeat the above until it says your disk is OK. Then continue with

mount -uw / 
launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServicesLocal.plist
launchctl list

Verify that the first command worked: you should see "com.apple.DirectoryServicesLocal.plist" listed in the "label" column. It will probably have a "status" of zero. The next command isn't strictly necessary, it just makes the dscl command quite a bit faster:

launchctl start com.apple.DirectoryServicesLocal
dscl localonly -merge /Local/Target/Groups/admin users youruser

If you want to check that "youruser" is now in the admin group, then

dscl localonly -read /Local/Target/Groups/admin users

should tell you. Then

reboot

You will now be able to login as "youruser" and have administrative privileges.

Membership of the admin group is the only thing that distinguishes administrative users from ordinary users.
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