Hi and Welcome to Apple Discussions...
When you booted from the install disk you were holding down the C key at the same time? If not...
Insert Installer disk and Restart, holding down the "C" key until grey Apple appears.
Go to Installer menu and launch Disk Utility.
Select your HDD (manufacturer ID) in the left panel.
Select First Aid in the Main panel.
*(Check S.M.A.R.T Status of HDD at the bottom of right panel. It should say: Verified)*
Click Repair Disk on the bottom right.
If DU reports disk does not need repairs quit DU and restart.
If DU reports errors Repair again and again until DU reports disk is repaired.
When you are finished with DU, from the Menu Bar, select Utilities/Startup Manager.
Select your start up disk and click Restart
While you have the Disk Utility window open, look at the bottom of the window. Where you see Capacity and Available. *Make sure there is always 10% to 15% free disk space*
If you cannot boot from your install disk, try booting in
Safe Mode
What is Safe Mode
You could also try running the Apple Hardware Test.
http://support.apple.com/kb/HT1509
If you have AppleCare:
http://www.apple.com/support/contact/
Carolyn 🙂
