Recovering data from after market internal hard drive

I previously installed an internal hard drive to my desktop running WinXP. The computer crashed and is unbootable.

What I want to do is to transfer the data from that hard drive to my laptop running Vista. I bought an aluminum enlcosure for the 3.5 internal hard drive and connected it via USB to my laptop.

The drive is recognized in explorer but I get a meesage stating that the drive needs to be formatted before I do anything else.

I obviously dont want to do this as my data will be lost. Any help will be greatly appreciated.