I am a mac user since 2003. As of right now I got 15 macbook pro and iMac 27''. On my iMac 27 i did not have password set up, but my brother for being such a foolish, he sets a password and is telling me he forgot. I can't even log in. I put the Mac OS X installer cd in and being holding C, but nothing works for me. The white screen with grey apple and the loading bar will stay on until I turn it off. Yesterday before going to work I did the startup from CD process, and when I got back from work after 8 hours, the loading screen was still on. I been doing this on my macbook pro for many years, the language screen comes up very fast, like 1 min after u hit C. I did the other process where u hit OPTION when it starts. That works but when I chose to start from the Mac OS X installer, the loading screen will be loading for hours. I don't know if there something wrong with iMac's or anything. For doing this I am using the internet optical driver. Maybe u need external optical driver ? Is there anyone who can help me with this problem.
Thank you
Hello, technically you don't need an external drive, if your optical drive is OK it should boot fine. Try booting in safe mode, to do this hold down the shift key while booting. If your mac boots, insert the disc and see if your Mac reads it and if it is OK. You also can use your MacBook Pro to check if the iMac apple disc is OK
If your mac is stuck in the grey screen it means that something is preventing your Mac to continue its boot process. Do you hear the chime sound?
You can try many different things like to boot your iMac in target disc mode (boot holding the T key) and connect it with a firewire cable like an external Hard drive to your MacBook Pro, and check it from there.
Or try the opposite boot your MacBook Pro in target disc mode and use its optical drive to boot your iMac, so you put your iMac apple disc in the MacBook Pro and try to run the password reset from there.
Check here for an organized list of booting options:
http://support.apple.com/kb/ht1533
If this doesn't work you can do other things, like booting in verbose mode, to do this you hold down the command and V keys and it will show you all the things that go behind the scenes when the mac is booting in UNIX, you will not have the visual interface that you are use to. Or Single User Mode. Before getting into this, check the first suggestions. Post here your results and I will try to help you out, as well as other MR members.
I think there is also a way to reset the password using UNIX commands.