Windows 7: Create simple volume

If you delete those two partitions all the way to the right, it simply means you will need those recovery discs to restore the computer. Since you have those discs created, you are fine. Just put those discs somewhere safe. My wife has an HP laptop, and the first thing we did was make those discs and then delte the partitions to make them usable space. You should be able to do all of this from within Disk Management as well...no extra software needed.

You are able to achieve your goal.
Step two in the tutorial using Partition Wizard may be easier.
If you haven't already download PW. Great program to have anyway!

Before repeating all the steps using step 2.
With PW:
Select the unallocated space as is.
Create a logical partition
apply.

see if it lets you.

That's just complicating the issue. No other software is needed. The error explains the problem...which isn't a limitation of Disk Management.

In the Partition Wizard program, right click the Windows 7 partition and click Resize then in the second dialog box that opens click to drag the slider all the way to the right.

click to enlarge


Then in the left pane Operations pendind column click Apply then Yes for the conformation dialog box.