Waiting for Login

Testing out an iBook G4, I was hoping to demonstrate a spiffy ATI Radeon demo I installed on my G5. Unfortunately this demo requires a Radeon 9800, and the stock video onboard an iBook G4 is a 9550 which lacks the oomph. The demo locked up and refused to quit, CMD-OPT-ESC quit or anything other than rebooting.

The machine restarted, but after the "Starting OS X" animation, I was left with the pointer in front of the default blue background, and no login screen. Mouse moves the pointer, volume/brightness/eject keys work... no login screen whatsoever.

Rebooted from the install DVDs, repaired permissions and repaired disk. No dice.

Reinstalled OS X with save/archive. No dice.

Here's what worked, and what I should have done first. Reboot using your install CD/DVD, holding down the C key to force boot from the optical drive. Wait for the multilanguage prompt to install, click continue and wait for the main installer screen.

There's a Utilities menu. Select Terminal: we're going bogey hunting for a corrupted login preference file.

At the prompt, enter:

cd /Volumes
ls

ls is Unix's directory command. You should see a listing of at least two devices: your boot CD/DVD and your hard drive. We're going to your hard drive:

cd /"Macintosh HD"

Unix is fussy about case sensitivity and spaces in file names. The quotes make it clear that HD is part of a file path and not a separate argument to be passed to the cd command.

cd Users/yourusername/Library/Preferences
rm com.apple.loginwindow.plist
reboot

Yeah, it was really that simple. If you're savvy to using single-user mode, you can get to the file (without the install discs) that way too.