What to do with "no bootable device insert boot disk and press any key"?

Question

Iron

The computer freezes periodically (sometimes once every 2 days, sometimes 2 times a day), regardless of the load and operating time, the picture does not change for a couple of seconds, then the blue screen and reboot, then either the boot is normal, or "no bootable device insert boot disk and press any key". After a few reboots, it boots from the hdd again.
The coolers rotate normally, there shouldn't be any overheating.
The computer is 6 years old, nothing has been replaced. I suspect the hard drive is failing.
Question: could it be because of something else, or is it not easy to find out?

Answer 1

Well, yes, hard is junk. Check the SMART values ​​using CrystalDiskInfo.
Or the hard cable goes out