If you try to manage BitLocker drive encryption on a computer that has had a user type in his/her PIN too many times, you may get this error:
BitLocker Drive Encryption Error
The TPM is defending against dictionary attacks and is in a time-out period.
To resolve this issue, run the Trusted Platform Management Module (TPM) Management console by running tpm.msc from the Run or Search box. In the TPM Management console, click on Reset TPM Lockout.
Click on I want to enter the owner password. (You do have the TPM owner password, don’t you? If you’re not backing it up to Active Directory, here’s how you can do it!)
Type in the TPM owner password and click Reset TPM Lockout.