Ok I got my machine to not crash with my hub, now I cant get it to recognize my WD My Book External drive

I have uninstalled usb drivers, I got it to see it one time then disconnect it and tried it on another computer NO go, retryed it on my machine and its not connecting?

WindowsXP sp3
WD 250gb My Book usb

"USB device unrecognized"

anyone have any ideas?