[Sarpedon]

I have just updated an older iMac from OS X 3 to OS X 4 Tiger. Everything was going well until the machine restarted. At this point it asked me to log in. I entered my name and password but the machine rejected it.

I’ve visited the Apple Support website “OS X: Changing or resetting an account password (Snow Leopard and earlier).”

This page suggests I work from the installation disk. Thus: Restart, hold down the C key, choose a language, from the pull down menu choose Utilities, Reset Password, select HD, select user and then fill in a new password.

The page warns not to select “Systems Administrator (root)” but that is the only user that is in that box.

If I can’t select a named user how do I reset my password?

[P]

It seems your user account has been deleted for some reason. Do you have a backup? If so, restore from that and try the upgrade again. It's possible to make a new account with some hackery, but if you had something in the user account, you'll want to get it back from the backup rather than doing that.

[Sarpedon]

I do not have a back up. This was not my first line computer but an older one I was trying to update.

So how do I do some "hackery"?

I'm all keyboard and fingers.

[P]

Shut down the computer completely, and make sure that there is no DVD in the drive. Turn it on, and as soon as you hear the boot sound, press and hold command-S until you see a command prompt. You are now in single user mode. As an extra safety precaution, you should check that the boot disk directory is OK. Type

/sbin/fsck -fy

to run the manual disk check (fsck stands for "file system check", and the -fy bit means to always apply repairs automatically). This is what Disk Utility does when you check a disk. It will run for a while, and then report back. If it says "FILE SYSTEM WAS MODIFIED", run the same command again until it doesn't say that. Once you get no errors, it's time to remove the safety net. The safety net in this case is that the disk is mounted as read-only, but we need to remount it as read-write to make the change we need to do. To do that, type

/sbin/mount -uw /

and your disk will be mounted with write privileges (mount is the command to add a new disk to the file system and usually takes more variables, but in this case we're changing a mounted disk to remove the write protection - that is what the -uw bit means. / is just the location of the disk - in this case, the file system root). With that bit done, it's time to do the actual hacking. When the installation is completed, Apple adds a small file to the disk to show that. We want to remove that file, so we can rerun the last part of the installation - except we're being excessively careful, so we will just rename it. First go to that directory by typing

cd /var/db

and then move the file aside with

mv .AppleSetupDone old.AppleSetupDone

With that done, all that is left to do is to restart. Just type

reboot

and your Mac should do just that. Start up normally, and you should get to the last part of the normal installation process where you can create a new account.

Hope this helps.

[Sarpedon]

Thank you P

It worked like a charm.

I must say I was very unsure about what I was doing. I hate going into the bowels of my computer but your clear directions were wonderful.

Your efforts are most appreciated.

John

[ghporter]

Great step-by-step instructions, P.