System Preference won't open - Apple menu dissappears

It sounds to me like something of yours was deleted while your daughter was logged in. Just as it in OS 9, when you are logged in as a one particular user, you can see hidden vital files in other users home folders. I suspect one of those might have been deleted, and is now causing you a problem.

Additionally, it doesn't even need to be hidden. I once was screwing around with themes, and some of my system icons suddenly had a red tint. I downloaded a set of standard Mac OS X icons, and started to replace them. I started with desktop-it asked me if I was sure to yadda yadda yadaaa....Well, I ended up deleting the desktop! And that screwed EVERYTHING up.

End of story: I needed to reinstall. For you, create a new user for yourself, and then just copy over your documents and files.

 

To reinstall just put your OS X cd in the drive, then reboot holding down the "C" key to boot from the CD.

 

1. Try repairing permissions

2. Can you try creating a new account for yourself as Solar Flare suggested. You could then transfer across your documents/ pictures etc. Leave the old ~/Library stuff behind. You'll get a new unbroken set of those when you create the new user. Maybe you'd like to take your mail with you. IIRC it's in ~/Library/Mail

3. If that fails re-install. It's broken.

 

Right, that would be 'fsck -y' and extents file overlap, IIRC. When you start into single user mode (cmnd-s at startup), type 'fsck -y' (no quotes) at the prompt. Repeat until there are no more errors. But to be honest, that sounds like the least of your problems.

 

-Solar Flare

Ok. Before you do anything arcane like creating new accounts, let's make sure the system behind them is ok.

First, "Repair Permissions" by booting from the original install CD. Apple Menu/Disk Utility/First Aid. Select the disk not the volume. If you select the volume, you might confuse yourself as you can't repair permissions on that, and the 'Repair Disk Permissions' button will be greyed.

Second, restart holding cmd-s to start fsck'ing (read that fast!) the machine.

Run it over and over until it stopss saying "*** FILE SYSTEM MODIFIED ***"

Once it says "This disk is ok" (or somethingorother), reboot, and see how everything is. You may still need to create the new account in the Accounts pane of System preferences (you probably have to do this from the other account).

If fsck'ing seems to do no good, it's time to get Disk Warrior. 'Course that's a good idea anyway.

That's enough for now, keep us informed.