did you install the esata drivers that came with the computer? If not, how about checking Windows update (assuming you use windows Vista/7) for aforementioned drivers. Otherwise, go to toshiba's website and try to find them. If you're sure you have the right drivers installed, (I'm assuming this is a laptop) remove all power sources from the computer, and press and hold the power button for a full minute (i'm not kidding, some manufacturers make it a full minute, so time it) then see if that helped.