usb hdd

MAC OS Does Not See My Drive. http://www.seagate.com/ww/v/index.jsp?locale=en-US&name=External_Drive_Troubleshooter_-_Mac_OS_Detection_Issue_-_My_drive_is_not_seen_on_the_desktop&vgnextoid=4ee24a3cdde5c010VgnVCM100000dd04090aRCRD
For usb hdd try this:

• Use the Seagate Troubleshooters ... ... Windows Does Not See My Drive ... http://www.seagate.com/ww/v/index.jsp?locale=en-US&name=Operating_System_Detection_Issue&vgnextoid=1b734a3cdde5c010VgnVCM100000dd04090aRCRD ... ... MAC OS Does Not See My Drive ... http://www.seagate.com/ww/v/index.jsp?locale=en-US&name=External_Drive_Troubleshooter_-_Mac_OS_Detection_Issue_-_My_drive_is_not_seen_on_the_desktop&vgnextoid=4ee24a3cdde5c010VgnVCM100000dd04090aRCRD