Window 10 is DEAD and how to COLD BOOT !        
Safe mode does LIVE !         

No more windows login screens happen and BSOD's now: Blue screens, of death. ( You know the HDD/SSD is not dead, tested it fully you did first, if yes ?it is just a sick Windows 10)
This is all about the infamous, W10 FAST BOOT, it is demented if you learn how it really works. (it's cute, and sexy , and fast, but demented)
The key problems with W10 is the missing F8 hot key and is the cure ! (off by default turn it on using this)
The 2nd key fact is the W10 does not cold boots now...,  it actually DE-HIBERNATES, the PC turned On,. A.k.a.  Quick boot or FAST STARTUP, feature (default)
This Quick boot can be called Quick death.  (and the reason this page below exists)
The PC  boots from a mirror image in the hiberfill.sys (a huge hidden file in C:\ (root) ( a cold boot real does not do that EVER, so F8 = Cold boot now and MS turned it off this simple F8 key)
If the PC has memory corruptions,  the imgage file is now a wreck, and you boot 1000 times and it will never self cure its self.
The cure is easy,  a real COLD BOOT.

This page is about Dead Windows 10, and all you can get is blue screens of death. (and endless useless auto recover mode screens) Please do not reload W10 yet. OKAY?
Remove all USB devices ( they can have corrupted drivers , so remove all that USB stuff)
Remove more  USB devices. (even keyboard /mouse) and if  a laptop remove the bad main large battery. Still failing? yes, then proceed.
There  are other cause can be wrong video card driver. (only if you played with that , can that happen)
One easy way to land here is BAD RAM (DDR), (best is to test RAM in safe mode, 1 stick at a time, until sure RAM IS OK)
 There are on memory tests on earth that can test any RAM 100% period ! Some are better sure. (that means memory test Apps.' of any kind) Running the OS and huge programs is the best test. (for sure huge video editors)

This page below is not about hardware failure (or was and corrected as in MY CASE) nor about black screens of death.

The PC will show a sad face screen in blue, (blue is the only clue it is a Microsoft window, popping up, confusing billions of folks that don't know what blue means, sigh.)
The next screen (you boot  2 to 3 times see if you get the below) Windows has no default F8 safe mode key, like w95 to W7 had, but does have this.

(It is only 3 clicks, this is #1)  THIS IS Auto recovery mode. Click See advance button.
This above took at least 2 boot fails  to land on the auto repair mode, in W10 (there are 3 ways to get to advanced, the above,  the Boot w10 install media and the F11 key that HP provides)
Press advanced and get. (or go there from the F11/or install media) to here.
There are 6 choices here.  In my cases below, the Startup Repair fails (that is because W10 is dumb, and can't even do a cold boot in this process, but WE CAN !)

Click the RED box. above, yours is not RED just the ABOVE IS FOR CLARITY.
Line 4 is the new W10 Safe mode.
See the above, now you know  where those geeks at  MS hide your F8 key, it's gone now but moved here. (W10) Enable Safe mode, F8 gone)
In my case I click safe mode then Restart and WINDOWS now works, I then reboot hard shutdown and  start over and my PC now runs like new, (the SAFE MODE deletes the hiberfill.sys data old )!!!

Nothing beats EXAMPLES:
My PC failed due to my SATA3 (6g) PCI-express card died, (put in new one) and guess what, the hiberfill.sys file is now corrupted. (a W10 feature that, but can be turned off)
OMG, hiberfil.sys is bad now. (it turns out  many things now can corrupt the windows boot files, not just a virus or bad hdd/ssd)

The other bad thing  is in safe mode the Control panel power applet, is dead, when lauched , all advanced modes are grayed out, cute no? (sarc off)
Get that clear,  in Safe mode, I can't turn off, hibernate. Dang ! MS loves to brick wall me here.
 CURE 1:
This is a temporary fix,  we do this fix the PC it runs great then we put it back like W10 had it before:
FIX #1,  In command prompt, you can in fact set legacy F8 back on, using command #1 below.
Cmd.exe (in run box type this) and run as ADMIN (called an Elevated Command prompt or the command  fails)  {It will say successful , if  it was}
  1. bcdedit /set {default} bootmenupolicy legacy
  2. bcdedit /set {default} bootmenupolicy standard
Reboot the PC ,power ON, and quickly hammer the  F8 key, just like you did for since Windows 95,  bingo F8 lives again ! and with it a fresh cold boot and all fresh windows kernal and its drivers. all fresh.
Photo of F8 working after above Red command is issued
No kidding it WORKS !

Once the PC boots and runs ok, you can regress the above steps and all magic image files will be refreshed and clean.
For sure hiberfill.sys  is renewed.

Method 2: (a 2nd way to skin a cat as grandad used to say)
HP year 2006 and newer the F11 key ,takes you to HP recovery mode (hammer the f11 at power button ON)
This only works on REAL HP computers that have not been HDD replace or freshloaded using a MS W10 install full. (I call this a not slammed PC)
Boot to windows 10 install DVD or stick (called install media now)
Then pick
Troubleshoot > Advanced Options > Startup Settings.

Command prompt fixes:

Don't forget command prompt mode above. and the below fixes in hand typed command line key strokes , users commands.

By opening an elevated command prompt (or above recovery page) and typing

Powercfg /hibernate off  (enter key)
These setting ,are global to all accounts.

Disabling "Turn on fast startup" FIXED the problem for me :)
Just go to Control Panel > Power Options > Choose what the power button does and uncheck the "Turn on fast startup".

This forces cold boot on , Fast start is off and hibernate off.)
and no more hiberfill.sys, MIRROR boots and fails. again.

powercfg -a      (full status message , only, and  does nothing to pc,it is a passive query.)
powercfg -h off  (means diable hibernate modes)
powercfg -h  on  (avoid using hibernate)
powercfg /h /type reduced  (reduces the file by half)saving ssd space.

To make W10 more fun (joking)   They moved lots of things out of control panel and in to settings panels. (I click settings, then power)
Click change, first, to ungray the below options.
Then uncheck "Turn on fast startup."  (this makes the boot slower but no more BSOD'S from the corrupted hiberfil.sys file again. ( but to be clear, it was bad hardware that caused this)

Enemy #1 ( If hiberfil.sys  gets corrupted (its not hard to)  The OS will not boot, and the recover mode fix startup repair files, fails to fix this simple common failure. (wake up MS)

GROSS hacking ways?
If in a panic, you might try deleting,  hiberfil.sys,  and let W10 find that and force a DEAD COLD BOOT. (even  a Linux boot DVD/Stick  delete it !)  {not tested by me, this delete action}
In the old days, we could delete all 3 sys files there and the OS would just rebuild them... (The OS sees it missing as the dirty bit, true and does a rebuild)
We  always could  delete 2 files, the hiberfil, and the swap files, infact we could even turn off swap memory totally with 24GB ram there,  but do not do that, or the system will halt out of RAM.
Keep in mind all files here are hidden, in CP +File Explorer optins, + view tab,  windows hides these from you.
If at wits end,  use Linux boot, and delete the 3 files seen above,  This would be at wits end, using linux and not reloading W10 from scratch and 100 APPS.  10 times more easy in fact.
If it repeats,  you have bad ram... or a bad driver,  The HDD is easy to test.
One other trick if the PC even boots at all, is disable drivers, on things you don't need right not, or just to test  the theory,  in Device manager.

Ok you are not booted to Windows 10, if not, the PC has hardware issues.

version 1.  10-7-2017