partitioning - Windows 7 - Free space on "Disk 0"

I'm having trouble giving "free space" back to my primary partition on my disk 0.

The operating system I'm running is Windows 7, and all of the disk management was done by using the disk management tool in Windows 7.

Originally, my hard drive (disk 0 - 465 GB) was giving it's space to partition 1 (COMPAQ C)

Then, I "shrunk" the C partition (COMPAQ C) and with the free space, I created new partitions on disk 0, for example now it's:
COMPAQ C - 200GB
BACKUP E - 20GB
MOVIES G - 50GB
I also have "free space".

With any free space I have, I try to "Extend" COMPAQ C, and the "Extend" option in the right click menu is shaded, so I'm not sure how to go about giving the space back to COMPAQ C.

P.S:
All of the space being talked about is coming from the same disk (0)

Any help?