I know this is a fairly common subject matter but I have tried just about everything suggested but with no success. detailed below are my findings, I was wondering if anyone better qualified than me could suggest a diagnosis? What does it do? I hear the fans and hard drive and see the white/grey boot screen with the apple logo and spinning cog. The cog will spin for anything from 5 - 30 seconds before freezing. Some disk activity will continue for a short time afterwards before everything grinds to a halt? I have tried: 1. SMC reset - Done, no change to symptoms. 2. PRAM reset - Done, no change to symptoms 3. Safe boot - Attempted, progress bar appears and fills but still will not boot with same result, white/grey screen, apple logo and spinning cog for up to 30 seconds before freezing. 4. Hardware test - Extended Test completed. 13mins 19secs - no trouble found. When rebooting aftert test usual sequence followed but no freezing of spinning cog. Continued to spin for 10 mins with no change...... 5. Boot from install disk - Attempted to boot from OS X instal disk but experience the same sytmptoms as a regular boot. Grey/white screen, Apple logo and spinning cog. Lots of activity from CD Drive, maybe 60 secods, then freezes. 6. "Repair" OS X - unable to complete, cannot boot as above Additionally, I have been able to undertake the following Single User Mode and run fsck. Run 1st time, issue resolved. Run 2nd time, disk appears OK. type exit to boot and boot process starts. Systems hangs on following line of text: Waiting for window server before finishing bluetooth setup Verbose Mode - will boot and runs some diagnostics. I am not knowledgeable enough to interpret the output here but this line stands out as possible issues?? Bug: launchctl: Please convert the following to launchd: /etc/mach_init.d/dashboardadvisoryd.plist I think that covers everything I have tried to date. Is there any more I can do from Single User Mode to resolve the issue? are there any other boot methods I can try? Thanks in advance for any assistance.