My Passport is not detecting if plugged in to my Laptop after booting

Dear Sir,

   My external HD,  WDBACX0010BBK-00, MADE IN THAILAND  is not detecting in my laptop (TOSHIBA).

  I noticed that if I connect to the laptop when it is swiched off  and then when I boot the laptop , the system is detecting and able to work . If I  remove the HD by stopping it and again If i connected while system is on then the system is not detecting the harddisk and system is getting stuck and I am forced to switch off the system.

could you please help me to solve this problem




Some driver conflict

try downloading the SES drivers and update the Firmware