kernel panic, you need to restart your computer...
Sounds like the hard drive has died and is causing the startup failure. Get a new SATA 2.5" internal hard drive. Your machine will use either the 9 mm or the 12.6 mm drives. Install the drive then start up holding down the "C" key. Go to the second screen pull down menu to Utilities > Disk Utility. Format the drive using the "write zeros" security option then give it at least one partition. Quit Utilities and continue with the system installation. When finished download and install the system updates.