Hi there
There's a free one you can download directly
GPARTED.
GParted -- Live CD/USB/PXE/HD
This can extend and manipulate partitions "on the fly" as it's a BOOTABLE "Live CD".
Works just like the old Partitionmagic software from Powerquest (before Symantec bought them out and bollixed it wholesale).
Don't worry about the Linux OS -- It's a GUI which even the most dedicated Windows user would have NO trouble in using
You get images of your partitions -- just use the mouse to resize them. The menu system is pretty foolproof as well. (Delete, Create etc etc).
Enc screenshot.
You can also create a USB bootable version as well.
(If you've ever used the Acronis Backup software from the bootable media you might not have also realised that it actually boots up a small Linux kernel before presenting the user with the GUI so don't be put off by the fact that GPARTED also boots up a small Linux kernel before going into the graphical mode).
Cheers
jimbo