that would indicate there is a problem with your C: drive.
The first thing to check would be that is is still connected since it is not seen at all by the OS. Remove it and re-seat it a couple of times to clean the contacts. If it still does not work, U have a dead system drive, OR you have a power problem to the drive, OR you have a problem on your motherboard.
Is it running. U should be able to feel or hear it running. If so, it is getting power.
Get an external drive enclosure and connect it to another computer.
If it is recognized and you can read it, you have a computer issue.
If it doesn't run, or it is not seen, it is trash.
If it is recognized, but U can't read it, it may be possible to recover files, but that is a senior class subject.