|windows normally assigns the next available drive letter to a new storage device. |
There is no such thing as the E port. Drive letters may change as connected storage devices change.
I am pretty sure you have two partitions on that device. One of them is propietory and you should NOT remove that partition. If you didn't want the features that allows you should have bought a different device. Look at the link below for an explanation of what you have.
As far as the second F partition, you should be able to remove any files written there, and/or format it. I recommend you not change anything other than deleting unwanted files on the F partition.