Feel free to send a working device back to the manufacturer, but after the technicians laugh at your incompetence for a few minutes, they may charge you a service fee and P&H for returning a working device. The won't waive these fees just because you are PC illiterate, and can't follow advice provided on a forum, or didn't call their tech support.
Try assigning a drive letter in the drive management console. Right click "MyComputer"->Manage
(Search for drive management) I'm not using windows atm, so can't telll you the exact place it is.
If it doesn't work, delete the USB controller in the Windows Device Manager (right click "My Computer" & go to properties, then find the windows device manager button midway down one of the tabs- find the usn controller section, right click + delete all usb controllers), and reboot the machine & then try to assign an unused drive letter to the USB device.