You should be able to use gparted, assuming Vista doesn't have something funky in the disk formatting that they haven't updated for yet. Create a live CD, and you should be good to go. Worked fine for me on XP.
http://gparted.sourceforge.net/index.php

One thing you might want to be careful about, sometimes laptops have a "restore" partition (Dell uses these, I believe) in place of sending you actual Windows and drivers disks, while others (HP does this) may have partitions for quick-boot DVD players.