Select the Recovery HD and click on the downward pointing arrow button. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Wait until the operation completes, then quit DU and return to the main menu. If no errors are reported, then click on the Repair Permissions button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. (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 it does not say 'Verified' then the hard drive is failing or failed. In the DU status area you will see an entry for the S.M.A.R.T. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list.

When the recovery menu appears select Disk Utility. Repair the Hard Drive - Lion/Mountain LionР”В«oot from your Lion Recovery HD. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X. If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. Wait until the operation completes, then quit DU and return to the installer. If no errors are reported click on the Repair Permissions button. When the menu bar appears select Disk Utility from the Utilities menu. After the installer loads select your language and click on the Continue button. Repair the Hard Drive and Permissions Pre-Lion/Mountain LionР”В«oot from your OS X Installer disc. Р”В«oot into Safe Modethen repair your hard drive and permissions : Start with a visit to: OS X Maintenance - MacAttorney. If your computer seems to be running slower here are some things you can do:

Install os x mountain lion mac pro 1.1