I was trying to get the translucent menu bar back (!) to see how the feature in 10.5.2 works, and I opened up terminal and used the command
sudo defaults delete /System/Library/LaunchDaemons/com.apple.WindowServer 'EnvironmentVariables'
I got an error saying that no object called 'EnvironmentVariables' exists, and the next time I restarted my computer, Mac OS X refuses to start up. It just sits there with the gear spinning, stalled.
Is there a way to recover without having to Archive-Install? I have the leopard install DVD with me, if that helps. Also, this is on a MacBook CD 1.83. TIA.