Computer does not recognize external drive - Maxtor Personal Storage 3200 (U01E200) 200 GB Hard Drive

Have you tried connecting it to different USB ports? Sometimes it works on one but not on another.

Does the drive needs an external power supply? Some models do, others works just by plugging them on USB directly - check your manual for this one.

Does the drive works on another computer? Test it to see if the problem isn't the drive itself.

Have you tried it on another OS? (You can download and burn a Linux Live-CD or even run it from a USB stick: http://www.ubuntu.com/download/desktop) - If it works on this, but not on your regular OS, may be a driver problem.

Does the drive needs drivers? If so (it's unlikely), you should install them.

If all fails (drive doesn't get recognized on another computer, doesn't use external power, doesn't work with other OS, doesn't need drivers) then the driver may be at fault, and you should return it.