Try removing any other USB devices plugged into computer.
All USB ports on a system share an alotted power "pool."
Try an alternate USB port on computer, preferably on the back of the tower.
Ports on monitors, front of computer, etc. are often underpowered.
Try installing a powered USB 2.0 hub (connected to a USB 2.0 port).
This provides standalone power to device, not sharing resources with other devices.
Check that you are utilizing a USB 2.0 port. (usually shown as USB2...host controller)
If unsure, look in device manager, and in "view" select "devices by connection."
If port is USB 2.0 check to see that a USB 1.0 repeater and/or cable is not being used.
This will reduce the communication speed well below the port's potential.
