Hi,
Please do try these troubleshooting steps that may help.
- First is to do 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 the same problem will persist, in BIOS press F9 to set it's default then press F10 to save and exit.
- Next to try is to set your HDD as the first boot device.
- If the same problem will persist do check for any BIOS version available from HP's website.
- If all these will not work I would also suggest to disconnect other devices connected to the laptop before booting it up and observe if the same problem will persist.
- Lastly, do try a different HDD if you have on available.