This error can mean a hard drive failure but not most of the time. In my case it is not a hard drive failure, it is the Bios not detecting the hard drive. I know this because when I bootable with a Windows bootable installer to install Windows 10. I noticed it found the hard drive and installed the OS. This error is very common on Dell Latitude 6430U and other Dell ultrabooks. I knew in the old days Dell laptops had issues but this is unacceptable for a modern laptop. Dell needs more quality control work. What I found interesting was a temporary fix for this that involves me hitting F12 when I see Dell logo or immediately after boot and selecting the boot from internal hard drive option. I think a permanent fix for this may be to flash a new bios but I would have to be inside Windows to do that. Most bios flashing tools are done inside Windows. Acer and some other laptop makers allow people to flash a bios that they download on USB. When I fix this permanently I will update this article (see below update). The image below is me booting into Windows just fine from the hard drive after using the F12 to choose the boot from internal hard drive option. Ok update I have found a fix for this. I updated the bios by downloading the Dell bios update for this laptop modem and then flashing it. After I flashed it, I noticed when I hit F12 I didn’t see the legacy boot option to boot into Windows 10 and so I went into bios and disabled secure boot and uefi boot. I even deselected the boot from diskette option in the drop down and made sure the hard drive option was on top of the list and hit save. When I rebooted Voila! it booted up just fine into Windows 10. I think what caused that original boot error was the fact that uefi secured boot was looking for the original Dell factory Windows to boot and wasn’t finding it. The hard drive is just fine. No more having to hit F12 just to boot. Below is Youtube video I upped about this.