I know there are a lot of questions similar, but what I think the problem is the space to the right isn't "unallocated" it's "free" space. However, I can't get this to change to unallocated. The option to delete partition on the free space is grayed out, the extend option on C: drive is grayed out. The only option on the free space is to make a new volume.

Which OS are you running?

Windows 7

Send a screenshot of your disk layout?

If your disk dynamic or basic?