Macbook Pro Stuck At Loading Screen

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.

Since you are also running Mountain Lion Server I suggest you first turn the server software off before reinstalling Mountain Lion and see if the same problem persists.

Can the HDD be recovered?

Maybe some of the data, but the hard drive is dying and needs to be replaced. If you want to DIY, you can easily do so. You should also buy an enclosure for your 'old' drive to see if you can rescue any data from it. You may have to resort to something such as DiskWarrior to recover data.

Good luck,

Clinton

The first thing I would do is repartition and reformat the drive. If this can be successfully completed then you won't need to buy a new drive.

Although DU cannot repair the drive it does not mean the drive cannot still be used. It may just need repartitioning and reformatting:

Drive Preparation and Installation for Mountain Lion

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

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.

3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.

4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

7. After formatting is done quit DU and return to the main menu. Select Reinstall Lion/Mountain Lion and click on the Continue button.

Yes, the data may be recoverable, but that depends upon whether the drive is accessible. If you erase this drive then all the data are gone. If you want to save your files then you would need to have another drive to which you could copy the recoverable files.

Essentially, what you would do is buy a new hard drive together with an external enclosure. Put the new drive in your computer, partition and format it then install OS X on it. Put the old drive in the external enclosure and connect it to your computer. If the drive is accessible, then you can copy your files to the new drive. After you have recovered your files you can erase the old drive and see if it is still usable. If it is use it as a backup to avoid being stuck in this same situation again.

Where is this partition button that you are talking about?