New HD encloser

[The Napster]

I just bought a new encloser for my two hard drives. I really need the info off of one of them, but when i hook it up to my computer and double click on the drive it says its not formatted and askes me to format it. How can i get to read the data on the disk? It worked fine inside my big computer. (laptop is what im trying to get it to work on) i havnt tried the encloser with my big computer yet.

http://www.newegg.com/Product/Product.asp?Item=N82E16817155515