Looks like you installed a default instance, then changed the Instance ID. (selected default radio button, then changed the ID)

You will need to uninstall what you have already done and then reinstall as per the screenshot, or create the Named instance as SQL2008R2 and change the instance ID to something like SQL2008R2_Named.

Generally leave the Instance ID box alone and let SQL handle that part.  Just changed the Named Instance text box instead if you want a specific name.