Reinstalling Lion Without the Installer
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. Alterhatively, 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: Select Reinstall Lion and click on the Continue button.
Note: You can also re-download the Lion installer by opening the App Store application. Hold down the OPTION key and click on the Purchases icon in the toolbar. You should now see an active Install button to the right of your Lion purchase entry. There are situations in which this will not work. For example, if you are already booted into the Lion you originally purchased with your Apple ID or if an instance of the Lion installer is located anywhere on your computer.
All right so I'm at least at the disk utility menu (a sight for sore eyes!) although after following your instructions and trying to repair the disk I get a message that says "Disk Utility stopped repairing Macintosh HD. Disk utility can't repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files."
A couple questions: I have a time machine backup of my computer so I assume my files should be fine. How do I reformat the disk and what exactly does that mean? Thank you very much for your help.
1. 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.
2. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID then click on the OK button. Click on the Partition button and wait until the process has completed.
3. 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.
4. 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.
5. Click on the Erase button. The format process can take up to several hours depending upon the drive size.
When formatting has completed quit DU and return to the main menu. Select Reinstall Lion and click on the Continue button.