Hard disk spins and light on but does not show up...

Question

I tryed puting hard disk ( Seagate Momentus 5400.2 60 GB ) from last computer windows xp into Sumvision 2.5'' EnclosureWXT-E 844. When usb plugged into HP PAVILLION 6000 with windows vista, red light comes on enclosure & disk spins but drive does show up in ''Computer'' .

Any help welcome,.