Cannot Extend Volume In Disk Management On Bootcamp

[Bunnylord]

I have been running bootcamp on my IMac for quite some time now, and I've began to run out of space on my C: drive. I have shrunk the size of my Mac OS partition, however I cannot extend the Windows 7 partition into the free space. I would prefer to do this without external programs, as I have had trouble with them before.
Also, here is an image of the Disk management window when I try to get it to extend.

 

[derekimo]

Welcome to the forum,

Unfortunately you will have to resort to a third party program because windows disk manager won't let you extend to the left.

The partition wizard bootable CD is a good choice,

http://www.sevenforums.com/tutorials/93322-partition-wizard-use-bootable-cd.html