- First right click on the drive that you want to lock.
- Select the option 'turn on bitlocker' as shown in the below picture.
3. Now click on the check box 'use a password to unlock the drive' and type your password and click next
4. Now click on save to a file option to back up your recovery key
make sure to save this file in a safe place so that if you forget your password you can use this recovery key to unlock the drive.click on the encrypt option to encrypt your drive.