How to fix "Missing operating system" error?

Question

Windows

Hello. Lately my laptop on windows 7 has been giving the error "Missing operating system". However, it worked well for several years. I did not download anything from the Internet (no viruses). It just turns off. When turned on, it shows this. After a while, it works fine again, although I didn’t move it from its place, didn’t knock on it, and didn’t even lift it (this is if the train moved away or something like that). Why is this happening and how to fix it? There is no USB or OS disk

PS: I did not find a normal answer on the Internet

Answer 1

Or the PC does not see the disk at all
Or the disk does not see the Windows boot sector ...
most likely the problem is in the disk itself
You can restore the boot sector by booting from a USB flash drive with Windows or CD
I would also advise you to check the disk in what condition it is in general

Answer 2

output: 837 errors occurred while transferring data.

the disk controller dies, with a high probability on the side of the motherboard (but it also happens on the disk itself), if it was a stationary computer, I would advise you to plug the sata connector, but is there an extra one on the motherboard of the laptop - xs.
with a guarantee, you can give an answer to 'what's broken' by changing the disk to another, obviously working one, if the glitches remain, it means changing the motherboard.