Bitlocker lockout
You are not allowed to change the pin and don’t remember the old one.
Option 1
To reset the TPM lockout
- Open the TPM MMC (tpm.msc).
- In the Action pane, click Reset TPM Lockout to start the Reset TPM Lockout Wizard.
- Choose one of the following methods to enter the TPM owner password:
- If you saved your TPM owner password to a .tpm file, click I have the owner password file, and then type the path to the file, or click Browse to navigate to the file location.
- If you want to manually enter your TPM owner password, click I want to enter the owner password, and then type the password in the text box provided.
If Step 1 did not work go to, Option 2
(be careful when you do this so you do not mess up entire BitLocker, this work when we did it, does not mean it will work for you)
Log in to BIOS on the machine, we will try to reset Security Chip memory by selecting another option, that will reset the chip.
If your OS or some other reason don’t want to run on that Chip selection, change it back.
More post about Bitlocker
Read more about here: https://docs.microsoft.com/en-us/windows/security/information-protection/tpm/manage-tpm-lockout