Can't recognize an external USB hard drive--a solution

Had the same problem with a generic USB drive case from TigerDirect with an old WD hard drive inside it. It was being recognized only intermittently which was making me crazy. Some days XP saw it, some days no.

Removing the USB connector from the USB hub, and then putting it into a new different port on the hub did not help the computer recognize the external USB drive.

But disconnecting the external drive from its power supply, and then disconnecting and reconnecting the USB cable at the external drive (with the computer on) led to XP SP2 seeing it and assigning a drive letter in Explorer. I dont remember if I reconnected the power supply or the USB cable at the external drive first, but it was nice to see it back in action.