TPM 0x8029010C: Unexpected result from TPM chip

30-second fix: Clear the TPM through Windows

What's actually happening here is the TPM session state got corrupted — maybe after a BIOS update, a crash, or a Windows update that reinitialized the TPM stack. The chip itself is fine, it's just confused about which session you're talking to.

1. Press Win+R, type tpm.msc, hit Enter.
2. If you see "The TPM is ready for use", click Clear TPM in the Actions pane on the right.
3. Restart your PC. You'll be prompted to press a key to confirm the clear during boot.

The reason this works: clearing the TPM resets the volatile state and invalidates all old sessions. The next time Windows talks to the chip, it starts fresh — no stale handles, no mismatched counters. You will lose any keys tied to TPM (like BitLocker — make sure you have the recovery key first).

5-minute fix: Update TPM driver and restart the TPM base service

If clearing the TPM didn't help, the problem is likely a driver that was replaced or corrupted. Windows Update sometimes pushes a generic TPM driver over your chipset-specific one. This is especially common on AMD systems using fTPM (firmware TPM) or Intel PTT.

1. Open Device Manager (Win+X → Device Manager).
2. Expand Security Devices. Look for "Trusted Platform Module 2.0".
3. Right-click it → Update driver → Browse my computer for drivers → Let me pick from a list.
4. If you see multiple drivers, pick the one from your motherboard manufacturer (Intel, AMD, or STMicroelectronics) — NOT "Microsoft".
5. Reboot.

Still no luck? Open an admin PowerShell and run:

Stop-Service TBS -Force
Get-PnpDevice -Class SecurityDevices | Where-Object {$_.FriendlyName -like "*TPM*"} | Disable-PnpDevice -Confirm:$false
Start-Sleep -Seconds 5
Get-PnpDevice -Class SecurityDevices | Where-Object {$_.FriendlyName -like "*TPM*"} | Enable-PnpDevice -Confirm:$false
Start-Service TBS

This fully reinitializes the TPM base service (TBS) and the device stack. The reason this matters: TBS is the Windows-side manager that translates API calls into TPM commands. If it's stuck or using a stale driver handle, you get 0x8029010C.

15+ minute fix: Firmware reset and re-provisioning

When the above fails, the TPM firmware itself might be in a bad state — not just the Windows interface. This happens more often on discrete TPM modules (like on some Lenovo ThinkPads from 2020-2021) or after a failed firmware update.

Do this in order:

1. Check BIOS/UEFI settings:
   • Reboot and enter BIOS (usually F2, Del, or F10 during boot).
   • Find the TPM section (often under Security or Advanced).
   • Toggle TPM from "Discrete" to "Firmware" (or vice versa) — this forces the chip to reset its runtime state. Save and exit.
   • Boot into Windows, then reboot back into BIOS and set it back to your original setting. This triggers a full re-initialization.
2. Clear TPM from BIOS: Some BIOSes have a built-in "Clear TPM" option. Do that instead of the Windows method — it's more thorough.
3. Update BIOS: Check your motherboard vendor's support site. A BIOS update often includes a TPM firmware update. For example, ASUS released a fix in BIOS 3405 for TPM command errors on X570 boards.
4. Re-enable TPM after clearing: Boot into Windows, open tpm.msc, and if you see "TPM is not detected", go back to BIOS and explicitly enable TPM under Security. Some boards disable the TPM entirely when you clear it.

Why does this work? The TPM is a self-contained microcontroller. Its firmware can get into an unrecoverable state if a command sequence was interrupted mid-execution (say, a power loss during TPM key generation). Toggling the TPM type or clearing from BIOS forces the chip to reload its microcode from flash, bypassing any corrupted runtime caches.

Note for BitLocker users: Before clearing TPM from BIOS, suspend BitLocker or have your recovery key ready. The BIOS-level clear removes all stored keys, including the SRK (Storage Root Key). Windows won't be able to decrypt your drive without the recovery key afterwards.

When none of this works

If you still get 0x8029010C after all these steps, the TPM hardware itself is likely failing. For discrete TPM modules, you can reseat the module (unplug, clean contacts, reinsert). For firmware TPM, check if your CPU has a known bug — e.g., AMD Ryzen 3000 series fTPM had stuttering issues fixed by a later AGESA patch. In that case, the real fix is updating to the latest BIOS with AMD AGESA 1.2.0.3 or newer.

I've seen this error most often on Dell OptiPlex 7080 units after a Windows 11 feature update. In those specific machines, the fix was updating the TPM firmware from Dell's support site (version 7.2.3.0, released Feb 2023).