First, are you sure that you are not using your I: drive? Your personal folders (My Documents, My Music, My Pictures) and Desktop are saved to the I: drive by default in the Drew image. We do this because our image client can install Windows on the C: drive, while preserving your I: drive, which leaves your documents untouched. The only way that your documents are going to C: is if you specifically redirect everything you save to C: or if you've corrected the I drive redirection in the registry. If GParted is showing 3GB used, it's probably referring to I:.
GParted's user interface is a little more complicated than other programs and you should check out the website for instructions on how to use the program. You should also backup your documents because repartitioning your drive can cause you to lose data.
Lastly, keep in mind that if you change your partitions and your computer needs to be reimaged at some point, the Helpdesk will have to completely wipe the computer and create the two original partitions again.
Software Support Specialist, Computing and Network Services