Impossible to Disable Secure Boot

[austintexas45]

I talked to support and they want me to send the laptop back for repair, I explained the issue, but apparently they want to see with their own eyes.  Maybe they will realize that this is a real problem and update their code or bug that is causing this behavior.  I will keep everyone posted.

[doughjohn]

Hi

In the OP you say this

With now everything set up as much as the BIOS allows me to enable Secure Boot, I Exit and Save. The cpu restarts and prompts me to validate a 4-digit code to enable Secure Boot. I do so. The computer restarts and seems to be booting the USB stick but immediately returns the following error message.

Secure Boot

Selected boot image did not authentica​te.

WHY?

If you want to disable secure boot did you enter a 4 digit code to enable it?

[lastwraith]

I realize this is an old thread but it comes up high in search results and there is no real answer posted. I struggled with this at a client site for way too long and finally got a real answer.

TL;DR

Numlock doesn't activate and when prompted for a 4 digit password the machine actually rejects you and settings don't save.

Use the number keys instead

Long version

Prob

On an HP with UEFI, settings revert back when trying to disable secure boot

Error msg - Selected boot image did not authenticate

Cause

NUMLock not being engaged when system prompts for 4 digit code upon boot

and/or

Fast boot is ENABLED

Solution

1 - DISABLE Fast Boot

AND

2 - Either use the number keys or hit NUMLock and THEN use number pad

HP should show numbers entered, "sing" some audio, and then UEFI settings should stick

[Robert-Floyd16]

I have some of these units to image. I found from BIOS go to Security and uncheck System Management Command. Then go into Advanced and Boot option, uncheck fast boot. Next go into Secure Boot Configuration. Enable Legacy support and secure boot disable. Also uncheck Enable MS UEFI CA key. Then save and exit.

Do not press any keys on the restart. It will prompt you to enter a four digit code. Once you enter it and press enter it will restart again. Then you can use esc to bring up other menu options such as pxe boot and the boot menu.

[Sw1ftb0nes]

I followed your instructions, but did not receive a prompt for the 4 digit code. As such, everything was returned the way it was, and I still can't push a build thru PXE. I've seen this code once before on a buid I created earlier, but now it won't come up. What am I doing wrong?

[lastwraith]

Update to the latest "BIOS" (UEFI really), reset to defaults, and try the instructions again?

[Sw1ftb0nes]

Yeah. Nice thought, but it's aready been done this morning. Thanks for the suggestion tho. Keep 'em coming.

[lastwraith]

Haha. What model are you working with?

[Sw1ftb0nes]

The HP ProBook 450 G3.

[rkparkinson]

I had the same problem with a Pavilion Mini 300-030.  I used the steps given (Win + I, Power, hold Shift while clicking Restart) to get into the Advanced menu.  Went into UEFI to change secure boot.  Told me to restart to change it.  When I restarted, it gave me a code and said "enter code and hit Enter to change boot security" or such.  On restarting went into BIOS and was able to change settings using SIDE ARROW KEYS!  Turned on Legacy and turned off Fast Boot and upon restart F12 and PXE worked.