When I turn my computer on, all I see is a black screen with this: 
DISK BOOT FAILURE - INSERT SYSTEM DISK AND PRESS ENTER
No boot device available, press Enter to continue
What should I do?
This message usually indicates that the computer is unable to find the operating system on the hard drive and therefore cannot boot. There are a few steps you can take to troubleshoot this issue:

1. Check the boot order in the BIOS: Make sure that the computer is set to boot from the hard drive that contains the operating system.
2. Check the hard drive for errors: You can try running a diagnostic test on the hard drive to check for errors. The exact steps to take this may vary depending on your computer's make and model, but typically you can access the diagnostic utility by pressing a key (such as F12) during boot-up.
3. Boot from a recovery disk: If the hard drive is not functioning properly, you may need to boot from a recovery disk or a bootable USB drive to perform a repair. You can use the recovery disk that came with your computer, or you can create a bootable drive using a program like Windows 10s Media Creation Tool.
4. Repair or reinstall the operating system: If the above steps don't work, you may need to repair or reinstall the operating system. To do this, you'll need to boot from a recovery disk or a bootable USB drive, then follow the instructions to repair or reinstall the operating system.

If none of these steps resolve the issue, there may be a hardware problem with your computer. In that case, you may need to take your computer to a professional for repair.
That seems to have worked, but when I started my computer it popped up a box telling me to Restart your PC to repair drive errors, should I? Also, it seems like my folders where I store all my pictures is gone, do you think that might be related?
It's posible that data on your disk was corrupted. You should restart your PC to let your system try to repair filesystem and see if that helps. If it doesn't you can download an application designed to recover data like Disk Drill (up to 500MB data restore for free) or Testdisk (free). You can also contact specialized data recovery service but it's more expensive option.
Unfortunately the automatic file repair didn't work, can you give me a list of the best file repair software