Data Lost..??

Hello,

I had connected my External Transcend 500 GB hard disk</gras> to a PC,but it doesnt detected, later when i inserted both the USB cable of my hard disk to PC usb ports, it get detected. Then i started to transfer data to PC,but it get hanged.Then i remove my Hard disk directly from PC.
Later when i saw my hard disk, it doesnt show the folder from which im transfering data to PC, but it is still showing folder space in properties.Then i clean up the disk.
Now i want to recover my lost data from hard disk as it contains importnat files.
Plz reply soon and helps me in this regard.