HOW TO FIXING EXTERNAL HD?

Good Day everyone,

I just want to ask if there anything i can do for external hard drive (Western Digital Element) 320 GB. What happened is the other day I was trying to re-format it using the software that will make it capable of installing WINDOW 7 from it. but unfortunately a power failure while it is formatting. Now when I plug the external hard drive, Windows can detect a new hardware but it cannot found a driver for it.

Thanks in advance