I have a compaq evo w400 that I use as a Data Server to sort massive amounts of Data. I have a 320 GB connected externally, useing USB. When I turn it on know it comes up that it needs to format the drive. However, if I connect it to another machine it is able to see the drive with out any trouble. I tried reinstalling the OS so that it could reconize it again an a differnt USB to only have the same thing still happen.Last TIME I saw this it was 2 times on 2 seperate machines and 2 different reasons:

# 1 - A faulty USB port. Have you plugged this into a different port.

# 2 - A 2.5" external hard drive and the PC 5 volt side power supply is weak to where the USB port is not supplying enough milliamps of power for the drive to operate. This can be corrected by either using a heavier DUTY USB cable to power the device or one of the cables that connects to 2 USB ports for extra amperage to power the drive.What's on the external HDD ? ?

What server OS are you running ? ?

What file SYSTEM is used on the external ? ?

You've been here long enough to know the drill...posting as much info as you can about your ISSUE to arrive at a resolution.
what is hdd space, 500gb 1tb or such. This might help as os's have litmits of what amount of drive space they can see depending on the the server version.Sorry, forgot I made this :/ Running Server 08 DataCenter x86, NTFS, 320 GB Maxtor, tried a differnt port. I know its not a power issue cause, it runs on my laptop but, I want to be able to ACCESS it from any where.I got this out sorted out mostly. I got a terra drive an moved everything off on too it connecting the drive up to the on board IDE. Formated the drive an put all my shows on it too then