Did a safe boot. Most of desktop is there, but top toolbar with apple logo and time/date, etc does not always appear. Reset multiple times...
None of the apps will run. Finder does not run.
You've given us ***** all information to work with. What does the ***** stand for?
When did it first occur? Moments before I posted.
What program were you running. Only Safari was open.
Was it from sleep or from cold boot? Sleep.
Did you make any significant changes via hardware or software before it happened? New battery about 2 weeks ago. New HD a few months ago.
Most importantly, what OS are you running? OS X Lion. I believe. Running disk utilities right now. Verify disk said HD was OK. Verifying permissions completed. Repair permissions currently running, est about 18 minutes.
My first suggestion would be to hold alt on startup and boot into the recovery partition if you can (if not boot from an install DVD).
Use it to access disk utility and check permissions and the drive health.
If both are ok then launch Apple Hardware test from the DVD and see if that comes up with anything.
I'm betting it's likely your hard drive that is failing though.
Confirmed OS X Lion 10.7.5
OK, it got down to less than 20 minutes remaining, then jumped to over 5 hours, then jumped to the Mac OS Utilities menu with choices to Restore, Reinstall, Get help or Disk utility.
Why is it not reinstalling Mac OS X?
Any help?
Can you get it into safe mode in a usable state?
If not it might pay to see if you can get access to another Mac, download Mavericks from the MAS and create a bootable USB.
There's a OS X Install ESD file on my desktop, which contains "Install Mac OS X Lion.app". Since it's been a few years since I got Lion, I don't recall if that file was meant for USB or executable from desktop. I clicked on it, but nothing is happening yet.
If you download http://liondiskmaker.com
It'll use that file to create a bootable USB for you. This means you can attempt an install without going through the world of pain that is an internet install (causes issues for me and my machine works.)