Next step if Vista won't see harddrive

1 - New Dell XPS 720.
2 - Just tossed in my 500GB Wedstern Digital.
3 - Shows up in the BIOS in the SATA 3 slot.
4 - Shows up in Device Manager. Seems to be fine.
5 - Doesn't show up in the Disk Management.

Any guesses on what to do next?

Have Vista Home Premium on the computer, and the HD was last in my Windows XP box(a previous 4 year old XPS). Is it because it was formatted on another computer or something weird?

p.s. All my music and backup files*from other computer is on it, so don't want to reformat it even if I had the choice.

This is a fresh computer with nothing really on it yet, think a fresh install of Vista will help it see the drive?