If the TPM has been initialized but has never been used, or if you want to use the TPM again after you have turned it off, you should turn the TPM on.

To turn on the TPM

1. Open the TPM Management (tpmadmin.msc) snap-in.

2. In the Action pane, click Turn TPM On to display the Turn on the TPM Security Hardware page. Read the instructions on this page.

3. Click Shutdown (or Restart), and then follow the BIOS screen prompts.

   After the computer restarts, but before you log on to Windows, you will be prompted to accept the reconfiguration of the TPM. This ensures that the user has physical access to the computer and that malicious software is not attempting to make changes to the TPM.

If you want to stop using the services provided by the TPM, you can use TPM Management to turn off the TPM. If you have the TPM owner password, physical access to the computer is not required to turn off the TPM. If you do not have the TPM owner password, you must have physical access to the computer to turn off the TPM.

You can also turn off the TPM to simulate or test the BitLocker Drive Encryption recovery process.

To turn off the TPM

1. Open the TPM Management (tpmadmin.msc) snap-in.

2. In the Action pane, click Turn TPM Off to display the Turn off the TPM Security Hardware page.

3. In the Turn off the TPM security hardware dialog box, select a method for entering your owner password and turning off the TPM:

   • If you have the removable media onto which you saved your TPM owner password, insert it, and then click I have a backup file with the TPM owner password. In the Select backup file with the TPM owner password dialog box, click Browse to locate the .tpm file saved on your removable media, click Open, and then click Turn TPM Off.
     
     
   • If you do not have the removable media onto which you saved your TPM owner password, click I want to type the TPM owner password. In the Type your TPM owner password dialog box, enter your password (including hyphens), and then click Turn TPM Off.
     
     
   • If you do not know your TPM owner password, click I do not have the TPM owner password, and follow the instructions provided in the dialog box and subsequent BIOS screens to turn off the TPM without entering the password.
     
     

Additional references

• Understand TPM Initialization
  
  
• Initialize the TPM