Did Windows 10 just add a partition to my hard drive?

I have two computers running Windows 10. Just today, I noticed that both of them have an additional volume with a drive letter assigned to them (one of them named "Local Disk (G:)" with 68.9 free of 95.0 MB, and the other named "SYSTEM (F:)" with 70.6 MB free of 96.0 MB). When attempting to open both of them, I receive the same error: "You have been denied permission to access this folder." Adding to the confusion, neither computer has this new volume listed in Disk Management.

Has anyone else come across this? Is it time to wipe, or is it part of a recent Windows 10 upgrade?

Thank you both for the comments. DarkMoon, I checked diskpart, and I figured out the answer after doing a bit of digging:

For some reason my computers assigned a drive letter to the EFI Partition. I ended up just unassigning a drive letter using the following commands:

    diskpart

    select volume=f

    remove letter=f

And there you have it, I cleaned up my Devices and Drives without damaging anything!