Cannot see external hardrive

In the process of installing a new hardrive in a dell inspiron and looking to reimage it with a Ghost Backup. The image is on a Western Digital My Book external hardrive (USB) but I cannot see it in the My Computer window on either the laptop, or the desktop that it has been connected through (backups occur through the home and wireless network). I can, however, see it in the device manager.
For some reason (most likely that it was late at night and I was bone tired) I had the external drive connected to the laoptop when I was formatting the new drive. could this have renamed it? I know that I only formatted the new drive. I have connected the ext. drive to the desktop, uninstalled it via the device manager and hooked it back up. It registers in on the tool bar but not in the my computer window.

Any and all of your expert advice is appreciated.

Right click the 'My Computer' icon and select 'Manage', then open the Disk Administrator. Does the drive appear here?

TB

Yes, I see it as an unallocated drive. I am guessing this means I need to format so the data on it is lost?

Sounds that way. Unallocated usually means the partition has been deleted. You'll need to create a new partition and then format.

TB