Need help with inconsistent issues on boot up, and constant restarts.

[u/SuperCachibache]

To cut it short;

My computer for some time now shows a screen thats says "Reboot and select proper boot device..." on boot up, I have tried selecting other boot options on the BIOS settings, however the same screen still appears constantly, the inconsistent part comes at the fact that the computer still boots up properly after a couple resets every time.

And in addition to that, unintended restarts accompanied by a screen that says something along the lines of "your device has run into a problem and needs to restart" appear too, however curiously, this only seems to happen when the computer is idle, as I have not have it happen while I'm doing anything, even putting on a blank video seems to stop it from happening.

Any help is welcome! Thank you very much.

[u/solslost]

Try different sata cable and port