Okay, you need a partition editor. Windows 7 can't do it.
Download this program, it's a free partition editor by EaseUShttp://www.partition-tool.com/easeus-partition-manager/comparison.html
Get the Home Edition. Install it and let me know when you run it.
Also, I noticed it's a Logical drive. It needs to be Primary Partition. Anyways just let me know when you are running easeus