I've never used an external drive before, but here is what I would check out in any case:
1) Does your motherboard support USB 2.0?
2) If so, is USB 2.0 Support enabled in the motherboard BIOS?
3) Does NEC provide you USB Drivers that you would need to install before you install your drive? Some USB devices that I've used in the past require software installation before hardware installation.
I hope this helps you.