Upgrading Dell T7910 Workstation from TPM 1.2 to 2.0 (Windows 11 "Ghost TPM" Reinstall Loop)

Hi

You all know me, and you know I aint no GhostBuster.....

However I still offer...

The usual fix for a Dell T7910 that gets stuck in a Windows 11 “ghost TPM” loop after a 1.2 → 2.0 upgrade is to fully clear TPM ownership, hard-reset the platform, then rerun the Dell TPM 2.0 firmware flow in the right boot mode. Dell and user reports for the T7910 specifically point to disabling TPM auto-provisioning, clearing TPM in BIOS/OS, resetting BIOS to defaults, and in stubborn cases doing a full CMOS/RTC drain before the TPM is recognized again. dell+2

What the loop is

The “ghost TPM” symptom usually means Windows thinks TPM exists, but the firmware/BIOS side is half-cleared or still owned, so the TPM reappears inconsistently after reboot. Dell’s guidance and community reports both describe this as an ownership/provisioning conflict rather than a dead chip. On older Precision systems like the T7910, a successful flash may still leave TPM reporting incorrectly until the platform state is fully reset. dell+3

Safe recovery order

1. Suspend BitLocker or any other disk encryption first, because TPM clearing can trigger recovery. dell+1

2. In an elevated PowerShell, run Disable-TPMAutoProvisioning. dell+1

3. Reboot into BIOS with F2, go to the TPM security page, and choose Clear if available, then save and exit. dell+1

4. In BIOS, load defaults once, then re-enable only the settings you actually need afterward. dell+1

5. If the TPM still ghosts, do a full hardware reset: unplug AC, hold power for 60 seconds, remove the CMOS battery, and on reports that matched the T7910 problem, also remove memory and boot with one stick during recovery.reddit

Reflash path

After the platform is fully reset, rerun the Dell TPM 2.0 updater from a supported environment. Dell community guidance for the T7910 says the update may need Legacy boot for the DOS flash path, even if Windows-based updating is flaky. If Windows 11 is already installed on that machine, note that the T7910’s CPU platform is commonly unsupported for Windows 11, so the OS may have been installed in bypass mode even if TPM 2.0 is fixed. dell+1

BIOS settings to verify

After the flash and hard reset, go back into BIOS and confirm:

• TPM is On and Enabled.

• Auto-provisioning is later re-enabled in Windows.

• Secure Boot and UEFI are set as needed for your install path.

• Any “clear” state has been removed and the module now reports 2.0. support.microsoft+1

Verify in Windows

Once booted, run tpm.msc or Get-Tpm and confirm the specification version is 2.0. Then run Enable-TPMAutoProvisioning so Windows can reclaim and manage the TPM normally. If Device Manager or tpm.msc still shows no compatible TPM, the next most effective step is repeating the full CMOS/RTC drain plus BIOS-default reset, because that exact combination fixed multiple T7910/T5810 cases. support.microsoft+4

Practical T7910 recipe

The shortest working sequence most consistent with the reports is:

• Disable TPM auto-provisioning.

• Clear TPM in BIOS.

• Load BIOS defaults.

• Full power drain plus CMOS battery removal.

• Reinstall with one DIMM if it still misbehaves.

Re:  Tried everything to no avail.

OP should have kept posting in the other thread.  That way, users may see what OP had tried and any history of troubleshooting steps being done so far.  

For OP's main concern about creating Windows 10 installation as solution, take into consideration of the following:

First consideration, new Windows 10 installation may not change the greyed out "clear" check box.  Unless CMOS being reset and firmware restore to default.

Second consideration, running PowerShell to check Active DB for 2023 Secure Boot certificates:  Type, ([System.Text.Encoding]::ASCII.GetString((Get-SecureBootUEFI db).bytes) -match 'Windows UEFI CA 2023')

If the result =  True, any action to clear CMOS and/or restore BIOS firmware will cause issue to the Windows 11 boot drive.  Because of mismatch of default and active secure boot certificates.

@anne_droid​ Thanks so much for your very detailed replay. I very much appreciate it.

Unfortunately, I cannot follow your suggestions. As I stated in my post I cannot get past step 1. Disable-TPMAutoProvisioning will not run on my desktop in Powershell because my Windows 11 cannot find, recognise or connect to my TPM. Whenever I run Disable-TPMAutoProvisioning I get the message (something like), TPM not found.

This is why I was thinking and asking advice about resinstalling Windows 10, then updating to TPM 2.0 and finally restoring my Windows 11 system from a Macrium backup. Would this work? Do I risk getting locked out of BIOS?

Given that my Windows 11 cannot find my TPM 1.2 would draining the power, removing the battery and disconnecting the TPM chip do any good?

Thanks again for your suggestions

Hi

I got nothing.

If the ELEVATED privelege level of PowerShell fails then I am stumped.

I wish youluck. 

@Chino de Oro​ Thanks for your suggestion. I very much appreciate it.

I ran [System.Text.Encoding]::ASCII.GetString((Get-SecureBootUEFI db).bytes) -match 'Windows UEFI CA 2023' as you suggested and go 'False' as a result.

Does this mean I can go ahead and drain the workstation power by holding the power button down for 30 seconds, then remove the cmos battery and finally unplug the TPM chip from the motherboard?

The result =  False meaning no 2023 certificates in the active database yet.  You can clear CMOS using jumper and reset BIOS firmware to default.  Hopefully, that should allow you to clear TPM and updating it.