I forgot my administrator ID

Please carefully read and follow:

http://support.apple.com/kb/HT1274

Hi Michael,

1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.

2. When your computer finishes starting up from the disc, choose Utilities from the Installer menu at the top of the screen. (In Mac OS X 10.4 or later, you must select your language first.)

Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access the Menubar at top.

1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.

2. When your computer finishes starting up from the disc, choose Reset Password from the Installer menu at the top of the screen. (In Mac OS X 10.4 or later, you must select your language first.)

Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Reset Password.

G5 or Intel? It can't be both.

Must in fact be Intel as you're running 10.6.8.

Insert your grey disc 1, or the Snow Leopard retail disc if you upgraded from the original OS.

Restart and hold down the C key at the chime. Hold the key until the spinning gear icon appears.

When the Mac finally boots from the disc, 'OK' the language screen, then wait a few seconds for the menu bar to load at the top of the screen - DO NOT click on 'continue'.

In the menu bar you can select password reset; I think it's in the Utilities menu, but if not just try the others.

When you've done with just quit the install er and reboot to the internal drive.

Should be sorted.

Another Hat Trick!

iMac G5s aren't Duo Cores. So Unless you have two or more machines, you have something wrong with your profile. But fix that once you figure out how to login. See this article on how to reset your password: http://support.apple.com/kb/HT1274

Yikes, sounds like serious HW problems, most likely the Hard Drive. 😟