Updating firmware caused my m.2 ssd to not work how to revert to old bios when I don’t have a restor

[Omen1231]

Hi I have updated my bios from hp.com and now my pc wont boot with my m.2 ssd drive inserted.  I have for almost a year been trying to downgrade to my old bios with no success.  I have went on hp.com and downloaded my older version and put it on a usb but cannot get it to downgrade.  Please help me with a procedure.  

[Bill_To]

Greetings @Omen1231 

Welcome back to the Forum.

Doing a BIOS rollback on a HP MB is a fairly complex process because HP tries to prevent users from doing this.

HP stores the latest BIOS.bin and BIOS.sig files in the 100 MB Windows EFI System partition.

So you may have to use Command Prompt or PowerShell to remove these files to prevent a BIOS update loop to the latest BIOS after doing the BIOS rollback. Or you could back up data. Then do a clean OS installation.

You need the following items to flash the BIOS outside of the operating system:

1. A Hiren's USB rescue flash drive.

2. The Aptio V AMI Firmware Update Utility.

3. A prior HP BIOS update for your PC's MB.

Check this HP Forum post on what needs to happen to do a BIOS Rollback.

This procedure could corrupt the BIOS making things worse. Sometimes you may have to use a Serial ISP Programmer if the AMI BIOS update Utility screws things up. Or even replace the MB BIOS chip.

I suggest having a local PC do the BIOS rollback. The Tech should make you whole if the BIOS rollback attempts brick the MB.

Regards