If you unhid System and Hidden files in Control panel>Folder options then there is nothing on D or E. You can hide them again.
If you click to enlarge and look at the screenshot carefully, the area I marked with the handwritten X is where to rightclick next to your E partition and choose Properties. Then click on Volumes tab.
If you can't find it it really doesn't matter to know what kind of partition it is - since it's empty you can delete it.