Will it boot into Safe Mode?
If does boot into Safe Mode then you have a program interfering with System files on your OS X machine.
If it doesn't boot into Safe Mode then most likely your hard drive is starting to dye and old Hollywood style death, slowly. Then just pray you have a viable backup and replace your internal drive.
Last edited by Satcomer; July 3rd, 2012 at 05:47 AM.
Mac Pro Dual 2.8 Quad (2nd gen), 14G Ram, Two DVD-RW Drives, OS X 10.8.3
2006 Mac Book Pro 2.16 (first Gen) OS X 10.7.4
2TB Time Capsule, 2 TB
32G iPhone 4S Black, iPad (3rd Gen) 32G Black