Might be your HDD have crashed, but here are some steps to follow to look for other solutions.
1. Might be that you will be needing to open your laptop, re-attach your HDD to the cable.
- Maybe it just got loosen that's why it crashed.
2. Might be that your cable needs for replacement.
- Your cable is the bridge for the laptop to read Windows on your HDD, if cable is damaged, Windows will not operate.
3. If you think HDD is damaged, then best thing to do is to try connecting it to another laptop. That's one of the best way to troubleshoot.
4. All files that is on the HDD (if it is damaged, HDDs are sensitive), then all files on HDD would be lost. But if it is only corrupted, you may use a File Recovery Program. Try Recuva, it restores some files that are lost on HDD corruption.
5. Lastly, if the HDD is really damaged, replace it with new one, just don't forget to check what kind of HDD it is, if it is IDE or SATA, they both have difference depending on the laptop that you have.
This would lessen your expenses if either one of the 4steps are right, hope that helps you out