[hanyoon]

1. I'm not an idiot, caps lock is off, num lock is off, I am using the correct password.
2. When I type in an incorrect password, the screen shakes as it's supposed to. When I type in the correct password, the screen changes as if it is about to log me in, but goes straight back to the login screen in a second or two.
3. I have gone into single user mode and created a brand new admin account. Same thing, doesn't log in.
4. Safe mode does not work either.
5. Guest account is the only thing that actually works.

I've been a PC user for almost 8 years, so I am relatively new to this whole Mac thing. The problem I am getting does not appear to be a very common issue, as I can only find a few threads on Google that relates to this.

Last resort would be to reformat the computer -- I really want to avoid this option since 1. I have not backed up any files, and 2. This is my best friend's Mac, which he lent to me while he is spending a year overseas.

On a sidenote: The iMac fell on its side yesterday (yikes!), but since the Mac boots up and goes to the login screen, I doubt I have damaged the hard drive. However, since I am new to this whole Mac thing, I'm not 100% sure if the fall was the culprit of this issue. Anyone care to chime in?

[reader50]

It sounds like the OS has been damaged, which might come from drive damage - but only if you have a spinning HD. SSDs are not susceptible to head crashes. You didn't say if this is a desktop Mac or a notebook.

Do you have install discs for it, or even a spare external HD? This problem suggests booting from another disc and running diagnostics. Possibly doing a repair install of the OS, which preserves user files & settings.

[ibook_steve]

He said it's an iMac.

Steve

[hanyoon]

Thanks for the replies. I booted the iMac with the Recovery Disk, and I tried re-installing the OS. The HD in which OSX was installed in does not show up -- so I tried deleting the partition. However, it gives me an error that says "Volume Erase Failed - Couldn't open disk." Does this mean my hard drive is done?

[reader50]

If you erase the original partition, you WILL lose all your data.

The original volume has some damage. You should check the HD with Disk Utility. Actually, you should back up everything first, unless your Time Machine backup is up to date.

[hanyoon]

Originally Posted by reader50 

If you erase the original partition, you WILL lose all your data.
The original volume has some damage. You should check the HD with Disk Utility. Actually, you should back up everything first, unless your Time Machine backup is up to date.

I've already ran the disk utility, but it keeps failing. It acknowledges that something is wrong when i check the disk, but it refuses to repair.

[reader50]

What does it say, exactly? Use the Verify Disk button. Depending on what it finds, DU may not be the best choice for the repair, so use the safe option first.

btw, select the drive hardware icon, not the volume icon for the test. That way it may spot problems in the partition table along the way.

[fritzair]

I am not at my machine right now so I can't lead you through the step by step.
Best thing you could do is go to the Apple store after you make an appointment, it is a hassle but they can help you.
If that isn't an option, in the past, you could change the password from a startup disk if you booted from it. You said the guest account works so it may not be the disk drive. if you happen to know someone with a external drive with OS X on it I would use it to boot from that drive and use it to back up your account as best you can if the in-machine disk is working. (If the disk utility cannot verify or repair than it looks like you are in trouble), which brings you back to my first suggestion-bring it to an Apple genius.

Good luck and let us know what you find.
Mike

[I Wonder Why]

Taking it to the Apple Store may or may not be a good idea. If they are busy, they might just want to reformat and reinstall the OS. If you or a friend have any utilities like DiskWarrior or TechTool Pro, it would be good to run them (if you have them on an external drive or startup DVD).