Archive and Install as there is obviously something wrong with the OS.
The boot, as you describe it, does not get anywhere near the Auto Login procedure so I doubt messing around with the Terminal app will help you.
Boot from the install disk and carry out an Archive and Install.
P
I believe there is a permission error with my admin account. I am stuck at the "Grey Screen of Death" when I try to restart my Mac. I can't reboot in Safe mode so I've booted with Install Disc and ran Disk Repair and Permission Repairs...Still unable to restart and still frozen at Grey Screen with gears turning. I can access terminal by booting from Snow Leopard Install disc so was wondering if there is a way to disable Auto Login from Terminal? Hopefully, this will bypass the "corrupt" user that is set to Auto Login during startup.

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