Laptop: "read failure on internal hard drive"

This is a 6+ year old Dell Inspiron. The message underneath is "no bootable devices". When I press F1 to retry boot, the message just reappears.
I ran the Dell diagnostic last night and today returned to find "kernel stack inpage error" and "dump of physical memory complete" and the other messages above. Is this problem fixable or is it time to buy a new laptop?