HP 800 G2 TWR. Managing TPM 1.2 over Windows 8.1 issue.

[Charlie_Volts]

Hi everybody, Hope somebody can give me a hand with this issue.

When my new W 8.1 Pro x64 was fully patched, an error began to appear in the Event Viewer just on boot: Event Source: TPM-WMI | Event ID: 1794 and the event included inside a reference to https://go.microsoft.com/fwlink/?linkid=852572

https://go.microsoft.com/fwlink/?linkid=852572 goes to https://msrc.microsoft.com/update-guide/en-US/vulnerability/ADV170012 and this Microsoft document named "Vulnerability in TPM could allow Security Feature Bypass - ADV170012" makes exactly reference to this Event TPM-WMI # 1794.

The recommendation is to apply firmware updates which in the case of HP redirects to: https://support.hp.com/us-en/document/c05792935

I was so glad because I was absolutely sure to be in the right way but....... the HP support document lists a very large number of systems but not the mine. The most similar are HP EliteDesk 800 G2 Desktop Mini PC (TPM 2.0 & 1.2) and HP EliteDesk 800 G2 Small Form Factor PC (TPM 2.0 & 1.2) recommending in both cases to apply the SP87753.exe

Just in case it is necessary, in the device manager the TPM appears without the yellow triangle and the HW Id. are:

ACPI\VEN_IFX&DEV_0102
ACPI\IFX0102
IFX0102

So, what is the firmware update to apply in my HP EliteDesk 800 G2 TWR? Maybe the recommended for 800 G2 Desktop Mini PC and 800 G2 Small Form Factor PC  (SP87753.exe) is also valid for the mine?

Many thanks in advance

Charlie

[itsmyname · Accepted solution]

@Charlie_Volts 

1, HP EliteDesk 800 G2 Desktop Mini PC (TPM 2.0 & 1.2)

2. HP EliteDesk 800 G2 Small Form Factor PC (TPM 2.0 & 1.2)

3, HP EliteDesk 800 G2 TWR

My guess is that it is the same motherboard in all 3 systems, but packaged in different cases.

My suggestion is to run the SP87753.exe -- to the point where it creates a new folder inside the "C:\SwSetup" folder on your computer, and then pause, before clicking "Install this update".

Look for a ".txt" or ".html" file inside the folder, that describes, in fuller detail, the various motherboards to which the update is to be applied.   Hopefully, your system's "form-factor" will be included.

Finally, note that most updates do a "sanity check", to prevent updating your BIOS with incompatible code.

So, if the update refuses to install, you will know that you have the wrong software for your hardware.

[Charlie_Volts]

Hi itsmyname,

Your advice has been very very useful. I have been inspecting the sp87753.exe to find out what is inside and I saw a pretty 27 pages pdf document named "A User Guide for TPM Config and HpqPswd", an HP TPM Configuration Utility package, and 38 certified TPM FW BIN files.

The pdf document explains how to flash the firmware to the TPM, and also the different limitations depending on the O.S. , the format of the drive where the OS is installed (GPT or MBR), ......

I've just done a fast read of the doc just to know that I have to read it slower because there are many details involved. For instance, my W 8.1 Pro partition is on a MBR drive but TPM 2.0 is only supported by GPT drives. MBR drive asks only for TPM 1.2.

I know i may convert my drive to GPT but my backup tool would be also involved as it doesn't support GPT drives. And so on, you know... 😉

Anyway, now i am in the right direction. As you wrote, the pdf doc lists the OS's and platforms supported and the mine is included.

Many thanks for your help

Charlie

[Charlie_Volts]

Hi again itsmyname,

I come back here to tell you that the "HP TPM Configuration Utility" works like a charm.

I have already updated the TPM firmware and as expected the error Event Source: TPM-WMI | Event ID: 1794 has disappeared when W 8.1 is booted which means that the TPM firmware vulnerability has been resolved.

Wonderful!

Thank you so much again

Charlie