Downgrading to older bios version on HP Z420 - help required

[SDH]

I have checked on the BIOS upgrade process HP describes for the ZX40 family of workstations. In one place they have it correct, and in the ReadMe that is associated with the SoftPaq SP140182 they have it wrong (again).

For the older workstations from ZX20 back you could update BIOS from within BIOS by harvesting the .bin file from the unpacked SoftPaq and place it on the "top" level of a USB drive, and then navigate to that from within BIOS. Here is the incorrect instruction from the current ReadMe (which looks like a partial copy/paste job from one of the pre-ZX40 workstation's documents):

From the ZX40 family and forward the newer HP BIOS for workstations wants you to nest the .bin file down 3 levels of directories on the thumb drive. The "top" level folder is to be named Hewlett-Packard and inside that is to be the next folder named BIOS, and inside that is to be a 3rd folder named New, and inside that is to be placed the .bin file. Here is the correct information from HP for doing that:

I sure wish they would do a better job of creating the documents. The newer BIOS is significantly more complex than it used to be and to provide incorrect instructions just compounds the issue. I just reflashed the latest BIOS in my Z440 doing it the correct way and it worked fine using the latest .bin file. When I tried that the incorrect way it did not. So, HP did not change the coding inside this newest version of BIOS. BIOS still looks inside that same nest of 3 directories to find the .bin file, and only then can it work with that. The whole idea here is that the safest way to update BIOS is from within BIOS.

For HP: Here are two links that have this incorrect:

https://ftp.hp.com/pub/softpaq/sp140001-140500/sp140182.html

https://support.hp.com/soar-attachment/735/col83845-vc-290587-1-vc-290587-1_sp140182_releasedoc.html

[joselso]

It should be noted that similar equivocal instructions by HP are also presented with latest HP BIOS update v.02.82 for Z6-Z8-G4 workstations in the update package SP140086.exe.

1. When extracted, the following document SP140086.cva (using Notepad.exe) reads:

Copy the binary to the following directory on the USB key: drive letter\Hewlett-Packard\BIOS\New

2. However, extracted from the same SP140086.exe package, a second document WS_Flash_Instructions.pdf states:

Copy the binary to the following directory on the USB key:
<drive letter>\EFI\HP\BIOS\New

3. Furthermore, in a third document named BIOS Flash.htm, also extracted from the same SP140086.exe package, it is stated:

...method requires that a removable storage device be present (typically a USB flash storage device) containing the BIOS binary image file in the \EFI\HP\BIOS\New folder.

So, in my view, it may be feasible to resolve this ambiguity by preparing a USB flash storage device with both locations present side by side: <drive letter>\Hewlett-Packard\BIOS\New\.bin file as well as

<drive letter>\EFI\HP\BIOS\New\.bin file

Their mutual presence will hopefully not interfere with each other, and the workstation BIOS will pick whichever path it is designed for.

Please advise.

[SDH]

If your BIOS is set to run in Legacy mode for your specific type of HP workstation use the nest of 3 folders as I described for the ZX40 family. If your BIOS is set to run in UEFI mode for your specific type of HP workstation use the nest of 4 folders that you found. Go figure!

I'm sure there is some logic to this for the Z4/Z6/Z8 G4 workstations but I don't personally know it. For the ZX40 family that 3 versus 4 difference is not described. I run BIOS only in Legacy mode, not UEFI, so I don't have personal experience with that issue in the ZX40 family. I'm a 1-trick pony...