"stop Code: Kmode Exception Not Handled" Issue

My HP laptop with Windows 10 hangs at bootup with the following notice:

"Stop Code: KMode Exception Not Handled." This notice is followed with "Preparing automatic repair" that hangs. I even waited overnight for HP to perform the "automatic repair."

STEPS I TRIED:
~ Ran diagnotics (F2). All h'ware passed testing.
~ Disconnected power, pressed power button for 30 seconds then tried to access Start Menu, tapping Esc key during bootup.
~ Forced shutdown twice (also 3 times).
~ Restored BIOS settings to default.
~ Set USB drive first in boot order and booted up with bootable Windows 10 boot tool on a USB flash drive.
~ During bootup, I tried tapping Esc, F9 and F10; but each effort leads to the "Preparing automatic repair," which hangs.

Is there anything else I can try?

 

Some HP systems ignore Esc/F9/F10 during certain fault states. Try:
* F11 immediately at power‑on (HP’s direct key for Recovery Environment)
* F12 (less common on HP but sometimes works)
* Shift + F8 (rarely works on modern systems but worth a try)

KMODE errors are often caused by drivers. A faulty peripheral can trigger the crash before Windows loads. Removing and reseting devices may help to find a faulty device or driver.

What is your exact HP laptop model? Is there a recovery partition?

See also:
How to Fix Windows 10 Stuck on Diagnosing your PC or Preparing Automatic Repair - MajorGeeks
Windows 10 Creates an Extra Disk Partition - MajorGeeks

 

Thanks you for responding. The sticker on the back shows "HP Model 15bsO13dx," but I do not know if its an HP Envy or other as I cannot access the PC (belongs to my wife). Tapping the "Esc" key let me access F1 (system info), F2 system diagnosis, F9 Boot options, F10 Bios setup, F11 System Recovery. But each option leads to the Stop Code.

I have never encountered such a failure. The hardware and components all passed testing. Resetting BIOS to default and changing the boot order for bootup with Windows 10 on a DVD disk or on a bootable USB flash drive also fails. I am disappointed in HP's technology: the HDD partition for recovery should be accessible. Maybe the MBR is infected!?

 

Problem solved! Windows in the partition that normally permits a factory reset became corrupted. Installing a fresh cop of the OS worked. I guess the Stop Code means failed OS. Since the S/N was inaccessible, I had to buy Windows again. Sigh!

 

OK, guess it's this model: HP Notebook - 15-bs013dx Software and Driver Downloads | HP® Support

 

Thanks. You are kind.