Acronis not assigning a drive letter for WD 1TB EARS

Acronis starts fine, no errors. I go to my disk under "Recover" and then "Browse" but my drive is not listed, only 2 things are, My Computer, No Name (C:) , - my USB with Acronis on it ) and Windows 7 (D:)

Acronis sees the drive if I click on destination, ( were to restore a back up to ) so, I'm not sure why I can't use it.
Selecting Disk 3 ( 1TB ) Shows the Partition Table as "GUID"

Its does however say "Unknown" Under Interface if it means anything.

I'v tried it as a USB drive and pluged it in a SATA port... same result.

O/S: (Backed Up) Windows 7
Mother Board: Asus M4A785-M
HardDrive : WD 1TB EARS ( USB Port ) ( With the image on it )

Also, Iv hooked my drive up to another computer and it would not "mount" it eaither, coincidence? ( unlikey i think )

Thanks :)