MyPassport 320GB doesnt works

For troubleshooting avoid using USB extension cables or USB hubs, also check if the passport is recognized on the disk management window. 

http://wdc.custhelp.com/app/answers/detail/a_id/1284/session/L3RpbWUvMTM1NzIyMzg2OC9zaWQvdmw4TW9uZmw%3D