If you want to allow the BitLocker without the Trusted Platform Module (TPM) in your Windows 7 system, then first you need to set the Windows 7 to use BitLocker without TPM.

NOTE: To use BitLocker without TPM, you need a USB Flash Drive which is used to store the recovery key. You need to plug the USB Flash Drive in before you boot your system so that the partitions containing the OS can be unlocked.

Follow the below steps to set the Windows 7 to use BitLocker without TPM:

1) Click on Start Menu and then type “gpedit.msc” (without quotes) in the Search box and hit Enter. It will open Local Group Policy Editor.

2) Then, go to the below location:

Computer Configuration\Administrative Templates\Windows Components\BitLocker Drive Encryption\Operating System Drives\

3) Then, right click on “Require additional authentication at startup” in the right pane and select Edit.

4) Then, select Enabled option and select “Allow BitLocker without a compatible TPM” check box. Then, click on Apply and then click on OK.

It will ask you to save the Recovery Key. Just save the key in the USB Flash Drive instead of a file.

Then, close Local Group Policy Editor.

5) Then, click on Start Menu and type “gpupdate.exe /force” (without quotes) in the Search box and hit Enter.

Once you hit Enter, a Command Prompt window will start running and displays “Successful” message.

Then, turn on the BitLocker using below link:

Turn On or Off Bitlocker Drive Encryption - iTechtalk

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