Clear-Tpm (TrustedPlatformModule) (2024)

Resets a TPM to its default state.

Syntax

Clear-Tpm [-UsePPI] [[-OwnerAuthorization] <String>] [<CommonParameters>]

Clear-Tpm -File <String> [<CommonParameters>]

Description

The Clear-Tpm cmdlet resets the Trusted Platform Module (TPM) to its default state.A reset removes the owner authorization value and any keys stored in the TPM.To reset a TPM, you must provide a valid owner authorization value.You can enter an owner authorization value or specify a file that contains the value.If you do not provide a value, the cmdlet attempts to use a value stored in the registry.

For more information on TPM, see the Trusted Platform Module Technology Overview in the TechNet library.

Examples

Example 1: Reset TPM

Clear-TpmTpmReady : FalseTpmPresent : TrueManagedAuthLevel : FullOwnerAuth :OwnerClearDisabled : TrueAutoProvisioning : DisabledLockedOut : FalseSelfTest : {191, 191, 245, 191...}

This command resets the TPM.The command uses the owner authorization value stored in the registry instead of specifying a value or using a value in a file.

Example 2: Reset TPM with a supplied authorization value

Clear-Tpm -OwnerAuthorization "vjnuW6rToM41os3xxEpjLdIW2gA="TpmReady : FalseTpmPresent : TrueManagedAuthLevel : FullOwnerAuth :OwnerClearDisabled : TrueAutoProvisioning : DisabledLockedOut : FalseSelfTest : {191, 191, 245, 191...}

This command resets the TPM by using the specified owner authorization value.

Example 3: Reset TPM using authorization value from file

Clear-Tpm -File "MyOwnerAuthFile.tpm"TpmReady : FalseTpmPresent : TrueManagedAuthLevel : FullOwnerAuth :OwnerClearDisabled : TrueAutoProvisioning : DisabledLockedOut : FalseSelfTest : {191, 191, 245, 191...}

This command resets the TPM by using the owner authorization value included in the specified file.

Example 4: Reset TPM with Physical Presence Interface

Clear-Tpm -UsePPITpmReady : FalseTpmPresent : TrueManagedAuthLevel : FullOwnerAuth :OwnerClearDisabled : TrueAutoProvisioning : DisabledLockedOut : FalseSelfTest : {191, 191, 245, 191...}

This command resets the TPM by using the Physical Presence Interface (PPI).The PPI does not use a value for owner authorization.

Restart the system for the clear action to take effect.The restart might require user input to approve the clear request.

Parameters

-File

-OwnerAuthorization

-UsePPI

Inputs

String

This cmdlet accepts the owner authorization value for the TPM.

Outputs

TpmObject

This cmdlet returns a TpmObject object contains the following information:

• TpmReady. Whether a TPM complies with Windows Server® 2012 standards.
• TpmPresent. Whether there is a TPM on the current computer.
• ManagedAuthLevel. The level at which the operating system manages the owner authorization. Possible values are Legacy, Balanced, and Full.
• OwnerClearDisabled. Whether TPM can be reset. If this value is True, the TPM cannot be reset through the operating system by using the owner authorization value. If this value is False, the TPM can be reset through the operating system.
• AutoProvisioning. Whether the computer can use auto-provisioning. Possible values are NotDefined, Enabled, Disabled, and DisabledForNextBoot.
• LockedOut. Whether a TPM is locked out.
• SelfTest. Information returned by a test that TPM runs.

• Get-Tpm
• Initialize-Tpm
• Unblock-Tpm