External hard drive (new) enclosure and Vista problem

Hi,

First of all Im not big on technical hardware issues but today I bought a Samsung 160gb external hard drive (in an enclosure) for my Toshiba M200 laptop which is running Windows Vista basic. Although Vista detects and installs drivers for the hard drive..the drive does not appear in ‘Computer’. I go to ‘Disk Management’ and I am unable to intialise or format the drive. The drive appears as unreadable and unallocated. I right click on the unallocated area and I dont get any other clickable options other than properties or help. The ‘New Simple Volume’ option is unclickable.

Can anyone help me fix this problem?