Can't boot into Windows?

So, I’ve got this HP laptop running Windows 8, and today it decided to just completely refuse to boot up into the OS.
It keeps hitting me with that blue screen showing those four little squares, saying "preparing automatic repair," while that tiny little loading circle just spins away endlessly.
After about thirty minutes of staring at it, the screen switches over to say "Diagnostic Your PC," but then it just hangs there for another half hour like it's taking a nap.
Once that finishes, I'm stuck looking at a pitch-black screen where the only sign of life is my mouse cursor moving around when I wiggle it.
I’ve tried restarting the thing several times now, but it’s like a broken record—it just does the exact same thing every single time.
I even tried being proactive and popped a Windows installation DVD into the disc drive, hoping it would kickstart things, but even after a reboot, it just ignores the disc and goes right back to that same loop.
Before that, I poked around in the BIOS, specifically looking at the boot manager options, and I noticed there are only two items listed in there:
-boot from EFI file
-notebook hard drive
It doesn't matter which one I pick; nothing will let me actually boot from that Windows DVD.
It makes me wonder, why on earth isn't the CD/DVD drive even appearing as an option in the boot list?
Does anyone out there have a clue what might be going on under the hood or how I can get this fixed?

There really should be an option to boot from a DVD drive so you can run a Windows repair... I actually dealt with something equally ridiculous a few years back on a different laptop—I had to flash the BIOS just to get the option to boot Windows 7 using legacy boot mode. It doesn't cost you anything if you have access to another working computer; you can just head to the manufacturer's website, grab the latest BIOS version, and run the update.

Oh, I just remembered—what about "quick boot"? You probably see that pop-up when you first turn the laptop on. Usually, it's one of those f10-f12 keys, so maybe give that a shot? There might be an option to select the optical drive in there.

It’s honestly kind of wild, I just borrowed an external CD/DVD drive from a buddy to try and get things moving, but after I rebooted and hit F9, I'm staring at this menu that only gives me two lonely options:
-boot from EFI file
-notebook hard drive

The external drive isn't even showing up on the list, which is just great.
I’ve poked around everywhere in the settings, but I can't find any sort of "quick boot" option to help me out either.

Oh, I totally forgot to mention, the laptop I'm working on is an "HP 15-d050sm"

http://support.hp.com/us-en/drivers/.../model/6786462

Like I mentioned before, why don't you just grab that BIOS update and get it installed? Once that's done, we can see where we stand...

Nancy Thompson8
Head into your BIOS and locate the Secure Boot settings; you'll need to set that to Disable.
Once that's done, make sure you enable USB Legacy support.
Next, navigate over to the Boot menu and configure the system to prioritize booting from your USB Drive.
Hit F10 to save your changes, and the computer will restart.

Before you even touch those settings, use Rufus to create a bootable USB drive containing the OS installation you intend to use.

LP

EDIT😛Since you attempted this using an external CD/DVD drive, enabling USB Legacy support is non-negotiable.