GParted is a free partition editor for graphically managing your disk partitions. The latest stable version of GParted is able to handle comfortably the following file systems. See Gpart -- Features. Please check before you use Gparted.
I have used the Gparted to shrink my D drive, and expand the "C" Drive on a Windows 7. I was pleasantly surprised that after dhrinking my D drive, I can move "D" Drive to the "free space" and create "free" space on the right of the C Drive. And all this is done with simple clicked, drag and drop.
Indeed a wonderful tool for System Administration