The following may help:
- If the external drive can be used with external power (instead of relying on the USB cable for power) try using it with external power (this is always recommended even if there are no problems).
- Try changing the USB cable.
- Try plugging the drive into a different USB port on your computer.
- If using a USB hub try connecting the drive directly to your computer or changing the hub. There have been reports of hubs causing problems.
- The problem may be with the enclosure, so if possible use a different drive enclosure.
- The problem may be with the hard drive itself, so if possible try using a different drive in the enclosure.
- Try it on another computer to rule out driver or hardware problems.
If you are receiving the error "The specified network resource or device is no longer available" then it may be that Windows is powering down the USB device. To stop Windows powering down the USB device:
- In Windows, go to the Device Manager
- Expand the USB Controllers node
- Right click a USB Hub node and go to Properties
- Click the Power Management tab
- Uncheck the box marked "Allow the computer to turn off this device to save power"