If you don't have any important files/settings/information etc. on the computer, you can try this.
Initiate a recovery procedure which supposedly restores the whole system to factory default. If it finishes without error, and you can start the system, we can assume that it was some kind of software error. When in Windows, you can run the checkdisk utility to be sure that there are no bad sectors on the hard drive.
If you do have important files, that you want to save, then there are two options I can think of:
- take out the hard drive, and connect it to another computer, for example via USB (with an external enclosure). If the hardware is OK, then you should be able to copy the files.
- create a bootable USB pendrive with an operating system on it, boot on it, and see if you can see the content of your hard drive from there. For example, you can create an Ubuntu system on a pendrive (>=1GB).