Well, the fact it will not work on two different computers is not a good sign.
The Disk Management window, showing the "Not Initialized" notation, does not look like a normal uninitialized drive. If I remember, it will normally show the space, even though not useable.
I will see if I can find a drive that will show uninitialized. Until then, you may want to download something like Partition Wizard to look at the drive. Maybe it could repair the partition and save your data.
Has the drive been making any strange sounds lately, or were there any messages about it?
Have you checked the Event Viewer to see if any errors show up regarding the drive?