Under those circumstances of the drive being external, drivers for the unit need to be loaded on the machine, have you done that?
For different operating systems my external HDD has drivers the only Operating systems that don't need them are Win2K and WinXP, but all the other windows operating systems do including Mac.
<b><font color=blue>"I wonder what was going through Custers mind when he realized he'd led his men into a slaughter?"</font color=blue>
<font color=red>"Sir! Custer was a pussy! You Ain't!"</font color=red></b>