iMac is stuck on apple logo and spinning wheel

Reinstalling Lion/Mountain Lion Without Erasing the Drive

Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.

When the recovery menu appears select Disk Utility. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu.

Reinstall Lion/Mountain Lion: Select Reinstall Lion/Mountain Lion and click on the Continue button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

You can only Repair Disk by booting from the Recovery Partition. How you boot to the Recover Partition is easy. When you hear the startup tone hold down the Option Key and choose it. Then open Disk Utility and run the functions. If your HD gets errors after 2-3 passes it needs the HD replaced immediately.

Are you booted into the Recovery HD per my instructions? Did you select your OS X volume?

As seen here:

In the example above you are selecting the volume below the main drive entry. Your volume may be named "Macintosh HD."

Your HD has failed, you need to have it replaced immediately. If you have been backing up this will be a minor inconvenience however if you haven't you are about to learn why backup is critical. If your machine is covered by AppleCare then simply call AppleCare adn they will walk you through what needs to be done.

Just because it says it's verified that doesn't mean it's healthy. It probably is not.

An invalid node is an error DU cannot repair. If you don't mind spending $100 for Disk Warrior, then I suggest you buy it because it can fix the error. Otherwise, do as the warning says. Backup your files. You will then have to erase the drive and reinstall. The procedure is:

Install or Reinstall Lion/Mountain Lion from Scratch

Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Erase the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.

2. After DU loads select your startup volume (usually Macintosh HD) from the

left side list. Click on the Erase tab in the DU main window.

3. Set the format type to Mac OS Extended (Journaled.) Optionally, click on

the Security button and set the ZeroData option to one-pass. Click on

the Erase button and wait until the process has completed.

4. Quit DU and return to the main menu.

Reinstall Lion: Select Reinstall Lion/Mountain Lion and click on the Install button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible

because it is three times faster than wireless.

If you have been backing up regularly then you can just restore from that backup. If you have no backup then you would need to try connecting to another Mac providing both the computers have a FireWire port. You would then connect the two by FireWire cable and use Target Disk Mode in order to access your computer's HDD. You might then be able to copy your files from the drive provided they are accessible from the other computer.

Unfortunately, there really is no way to know "why" it happened. There are many possible reasons. It's pretty much guess work without the proper testing equipment.

If the drive is restorable it may be worth the $100 to purchase Disk Warrior and then see if it can restore the drive's directory to normal.

I have just tried to instal the Samsung software for my new phone and the same thing happened, grey screen with the apple logo. I backed up all of my contacts on my iTunes prior to the installation. Would I be able to do the transfer from my iPhone4 to my galaxy s3 on another computer with the software?

Suzanne191,

Please create your own thread, what you are doing is very impolite which I am sure is not your intent. On the Internet this is called Thread Jacking. The reason it's impolite is while you may similar symptoms the cause is probably completely different. This makes the thread confusing and can take it off it's original focus. Please take a couple of moments, create your own thread and I am sure someone will be willing to help you out.

Thanks,

Wow thanks for your very RUDE response. Seeing as though on every other forum I have been in its considered impolite to start a new thread with the same topic I though it sensible to ask the kind people who answered Ben Suarez with his issue. Don't worry, seeing as none of the suggestions worked for him, I will be taking my machine to the closest apple store where I'm sure that someone will be able to assist.

Well had you read my response you would have seen it was not rude, it was to the point. With your attittude I'm sure you will get lots of positive responses. Good luck lady.