Okay, So I own a Western Digital 120 GB External Hard Drive. This hard drive has always worked fine for me until I plugged it into my computer and a message popped up that said "Power Surge on Hub Port" I clicked the little box for details, and it came up as.
USB Root Hub (6 ports)
Unknown USB Device
Unknown USB Device
Unknown USB Device
Unknown USB Device
Unused Port
Unused Port
Also, I have plugged in an Ipod and a printer, and they both worked. So if possible please help.