"Disk Utility stopped repairing Macintosh HD. Disk Utility can't repair this disk." What now? When I turned my computer on, it got stuck on a gray screen (nothing, no apple logo, but occasionally a spinning wheel, and I could move the mouse). I rebooted in recovery mode and got the various messages when I tried to repare using disc utility: "incorrect block count for file 0.indexDirectory (it should be 1508 instead of 754)" then "the volume Macintosh HD could not be verified completely." Then the alert that this disk could not be repaired.

Are there any steps I can take now? I have a couple of external hard drives so if nothing else, do you know how I can back up files from my computer? I don't have time machine or anything like that set up. I'm not very skilled with computers so anything will help, even if it's just "go see a professional." I have school assignments saved onto my hard drive so I'm really hoping I can salvage them.
With some minor skills and lots of luck you can try to repair it.

While holding the Command-S restart.

When it is done (if it boots) type "fsck -fy".

This will try to repair your disk.

You could spend $120 and get the more professional tool called DiskWarrior.

In any and all cases, back up your stuff.