Hello snoboarder Welcome to SF!
Another thought on that would be a drive returned to seller by previous customer where someone had simply wiped the data without cleaning the drive off fully or it was a drive tested while on the production line at the manufacturer from a batch of drives and ended up being shipped out for sale.
The later believe ir or not is the more likely explanation for a new drive if received in a sealed carton unopened. For a fast clean of that you can use a free security tool like
Eraser or open up a command prompt and use the Disk Part tool while sitll booted in Windows to nuke the drive entiirely before seeing a fresh new volume created and formatted for use.
Since the second drive is a 320gb model while the 7 host drive is only 120gb in size you won't have any problem using the following commands in Disk Part. The command prompt will open to:
C:\Windows\system\>disk part (start up tool)
list disk (lists all internal as well as external HDs, usb flash drives)
select disk #0 or #1 (you can easily see the size difference)
clean
create partition primary
format fs=ntfs
exit
The drive has been cleaned and seen a new NTFS volume added as well as formatted before you exit the tool and close up the command prompt. If you are worried about using the command prompt method and feel more comfortable using a gui the free drive tool
GParted Liive for cd will cover any future needs as well as clean this in no time while booted live from a cd or usb flash drive made bootable.