Hmm, problems.
I'm pretty sure that once created an Extended partition (containing the logical partitions C: and E: in your screenshot) cannot be resized. I had a similar problem and had to delete the logical partitions first, then delete the Extended partition, create the logical partitions again with bigger sizes. With Windows 7 in one of those partitions, that does not look like an option for you.
You might be able to create a brand new partition and move some folders from E: into it