Install latest chipset drivers.
Go into bios and see if your usb is enabled.
Use a different usb port.
Also hook up any other usb device into your usb, things like usb mice or keyboard or printer and see if windows detects them.
I have seen many people on this forum complaining about Vrebatim external drives. It is highly recommended for you to buy a new external USB drive from a different company and transfer the data to it through the laptop while you can.