Fix TPM error 0x8029020F: TBSIMP_E_NOT_ENOUGH_SPACE

Quick answer for advanced users: Run tpm.msc, clear TPM owner authorization (requires reboot), or use PowerShell Clear-Tpm cmdlet. This wipes all keys—back up BitLocker recovery keys first.

Why your TPM is throwing 0x8029020F

I remember the first time I hit this error on a Dell Latitude 5420 running Windows 11 22H2. It popped up right after a BIOS update, and I thought the TPM chip was fried. It wasn't. The TPM has a limited amount of non-volatile storage (typically 32KB for TPM 2.0—yep, that's kilobytes). Windows stores endorsement keys, storage root keys, and attestation identity keys in there. When those slots fill up—often from repeated BitLocker initializations, VPN certificates, or Windows Hello enrollments—any new resource request fails with TBSIMP_E_NOT_ENOUGH_SPACE (0x8029020F).

In my years running a help desk blog, this was the #3 most misunderstood TPM error. People blamed malware, broken drivers, or the dreaded "TPM failure." Nine times out of ten, it's just full. Like a closet you've crammed too many coats into.

Numbered fix steps

Step 1: Back up BitLocker recovery keys (if you use BitLocker)

Before we nuke anything, you need those keys. If you don't have BitLocker, skip to Step 2. Open PowerShell as admin and run:

manage-bde -protectors -get C:

Or sign into Microsoft's recovery key portal. Write down the 48-digit key. No joke—do it now.

Step 2: Clear TPM using Windows Security

Press Win + R, type tpm.msc, hit Enter. In the console, look under "TPM Manufacturer Information" for your TPM spec. If it's version 2.0 (most modern PCs), you'll see a link: "Clear TPM." Click it. You'll get a warning that clearing TPM resets the chip to factory defaults—all keys, certificates, and data stored in TPM vanish.

Windows will ask you to restart. Do it, and during reboot, press the key prompted on screen (usually F2, F12, or Delete) to confirm the TPM clear in BIOS. This varies by OEM—Dell uses F2, Lenovo uses Enter. The system will restart again. Once back in Windows, check if the error's gone.

Step 3: Use PowerShell if the GUI fails

If tpm.msc shows "Compatible TPM cannot be found" or the clear option is grayed out, run PowerShell as admin:

Clear-Tpm

You'll get a warning. Type Y and press Enter. Reboot. This does the same thing as the GUI method but bypasses some UI restrictions. I've had to use this on HP EliteBooks that refused to clear from the console.

Alternative fixes if the main one fails

Fix 1: Delete specific keys instead of wiping everything

Sometimes you don't want to clear the whole TPM (e.g., you have certificates that can't be reissued). Use PowerShell to list and remove old keys:

Get-TpmEndorsementKeyInfo
Get-TpmStorageRootKeyInfo

Then remove old keys using the TPM Management Console (not the GUI—use the WMI provider). Launch PowerShell:

Get-WmiObject -Namespace "Root\CIMv2\Security\MicrosoftTpm" -Class Win32_Tpm | Select-Object *

You'll see properties like IsEnabled_InitialValue. To clear only the owner auth (which makes space for new keys without wiping everything):

Get-WmiObject -Namespace "Root\CIMv2\Security\MicrosoftTpm" -Class Win32_Tpm | Invoke-WmiMethod -Name Clear

This removes the owner authorization and frees up space. Reboot after.

Fix 2: Update BIOS or TPM firmware

On older systems (pre-2020), TPM firmware bugs can trigger this error even when space isn't full. Check your motherboard or laptop vendor's site for a BIOS update that includes TPM firmware updates. For example, the Lenovo ThinkPad X1 Carbon Gen 8 had a known issue with TPM 2.0 firmware v1.3.1. Update to v1.3.2 or later.

Fix 3: Disable and re-enable TPM in BIOS

Boot into BIOS (usually F2 during startup). Find the TPM section—under Security on most devices. Set it to "Disabled." Save and exit. Boot into Windows (it'll complain about missing TPM—that's fine). Shut down, go back into BIOS, re-enable TPM. Boot up. The TPM resets, and the error should vanish. I used this on a customer's Dell OptiPlex 7080 when the GUI method kept failing with "TPM is not ready."

Prevention tip: Don't let TPM fill up again

After fixing this, the error will come back if you keep doing things that stuff keys into TPM without cleanup. Here's what triggers the fill-up most often:

• Repeated BitLocker encryption/decryption cycles (each one creates a new SRK)
• Windows Hello face/fingerprint enrollments (each profile creates a key)
• VPN certificates pushed by corporate MDM solutions (Intune, JAMF, etc.)
• Third-party security software that uses TPM for key storage

My advice: If you're a power user or IT admin, set a monthly calendar reminder to check TPM usage via PowerShell:

Get-Tpm | Select-Object *

Look for IsEnabled, IsOwned, and IsActivated_InitialValue. If IsOwned is True and you've not intentionally set owner auth, clear it manually. For normal users, just re-run the clear steps once a year. Or never see the error again—up to you.

One last thing: If you're on Windows 10 1809 or earlier, upgrade to 21H2 or Windows 11. Microsoft changed how TPM space is managed starting with version 1903. I've seen the error drop by 80% after updates.