Using bitlocker to protect your USB driver

1) bitlocker program comes with WIndows 7 Ultimate and enterprise, but not in basic
2) Insert your USB driver
3)In Windows 7, go to start menu, search bitlocker
4) You will see Bitlocker drive encryption under system and securities, run the program
5) You can see "turn on Bitlocker" near your USB driveico
6) Click  turn on Bitlocker and following instruction step by step and enter your password.
7) Done.