Inaccessible_boot_device error windows 10

[Lanric02]

I woke up today to find my computer stuck on a blue screen with the word 'restarting' on it with a white circle spinning. I shut off the PC and rebooted and came back to this same screen. I unplugged the Western Digital external drive and rebooted and then eventually got the INACCESSIBLE_BOOT_DEVICE message. Now when I reboot, all I get is a black screen and the computer seems to reboot repeatedly. Help!

 

[Lutfij]

1| Please pass on your full system's specs inclusive of your connected peripherals.
2| Have you made sure your BIOS is up to date(alongside the rest of your device drivers)?
3| Can you get to BIOS screen or at least into Safe Mode? If you can, please back up your critical content.
4| You may want to try and remove the battery from your motherboard for at least 15 mins before replacing it and trying again at booting up.
5| Now may be a good time to create a bootable USB installer. Speaking of installer, is this installation of Windows 10 based off the free upgrade path or via a licence key?

Further reading:
http://www.tomshardware.com/forum/id-2760985/inaccessible-boot-device-reset.html
http://www.thewindowsclub.com/inaccessible-boot-device-error-windows