On Mon, 24 Jun 2013 18:20:19 -0400, Brian Dude wrote:
Thank you for showing me this utility. I've never used it before, but, I
got an error:

DiskPart failed to extend the volume.
Please make sure the volume is valid for extending.

I forgot that it can't extend the system partition since it's being used.
You'll have to use a partiton manager from a bootable CD like George
mentioned.