If BitLocker appears to be unavailable:
  1. Search for BitLocker or encryption in the Start menu or screen:

  2. If unsuccessful, open the System Control Panel and select Get more features with a new edition of Windows link. Reinstallation of Windows is not required (only a change of the Windows product key is required). If you decide to upgrade to a new version of Windows instead (e.g. Windows 7 to Windows 8) and you have the system drive encrypted by TrueCrypt, it must be decrypted first (the upgrade requires reinstallation).

    Alternatively, search for edition in the Start menu or screen: