Why is there a gray screen and os x utilities pop up
My computer had a bluish screen and a spinning pin wheel cursor, so I shut it down. When it turned back on, a gray screen with OS X Utililities popped up. I have a back up disc but am afraid to use it to restore since it says that it deletes off it. How do I get back to my old computer with everything I had before? Has it crashed?
iMac with Retina 5K display, Mac OS X (10.5.6)