After restarting i got a sign that says "no bootable device".

A few days ago i was playing and my pc wasnt working properly, so i did a full scan but before the scan could be complete there was a 'error' and it said on the computer that it has to restart. After restarting i got a sign that says "no bootable device". So i restarted the coumputer a few times and nothing worked and then there was no sign that said "no bootable device" now there is just a black screen with white letters,

[edited for privacy (subject title edited to better reflect the issue)-please do not post personal or unique information such as but not limited to full names, email addresses, phone numbers, full serial numbers, etc.]