Hi,
Here are some troubleshooting steps that may help.
- Start with a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then try booting it up again.
- If these doesn't work do load BIOS and reset it to default by pressing F9 then test it again.
- Next to try if these doesn't work is to load BIOS again and make sure your HDD that has Windows installed is set as the first boot device.
- Again if these will not work make sure that the HDD is seated properly into the laptop.
- Take it off then put it back in making sure it's seated properly.
- If all these will not work your last option is to test the HDD into a different PC and if it doesn't work replacing it would be the only solution.