ugh, the way my stomach and heart dropped when I read that – can only imagine how that felt for you, I'm really sorry for your loss even when you just lose time and temporary peace of mind, it sucks.
Can you select and start from your usual boot drive in the bios? If yes try that. Otherwise you can create a bootable usb drive (linux or win, depending on what you are using) on another pc and attempt to repair it or at least get important data off your pc
It's probably an issue with your master boot record. The worst part about a broken computer though is that you usually need another computer to fix it.
Hardware is probably still good then. Probably a system update got a power interruption. But it could be something dumb like windows decided it didn't like your hardware anymore.
Now is the obvious time to recommend Linux, but I'll spare you that. I will say though a Linux LiveUSB would be handy for recovering your data though. Any maybe you can have a look around then.
If not then replace or reseat the two cables that provide power and data bus to the drive and try again.
If the bios sees the drive then use a windows environment to make sure the efi/mbr is working okay. This can be a multi step process. Medicat usb has a windows environment and here’s the Michael Dell company on the step by step process.
To recover data: have some device to put data on. Have some way to boot the computer like the medicat usb I linked earlier. Boot off your usb and pull everything from the /users/ directory. Unless you’re hiding sailor moon porno in /system32 then you’ll be fine with that.
I have a new computer coming next week and the only important shit I have on here are some automatic account logins so once I do all that I'll be back up and running I just had hoped it would last another week. The SSD or motherboard are toast I think.
Yeah, enter the BIOS/UEFI (usually like f10 or f12 on boot, depends on manufacturer of the system/mobo).
See if you can change the boot options to default to the drive Windows was installed on. I've seen this happen when the computer is set to boot to USB on priority and someone left a non-bootable usb in a port.