Hi Sam
I am Dave, I will help you with this.
That System Reserved drive is a system partition on your hard drive that is normally hidden, but because it now has a drive letter you can see it.
That partition may appear empty, it is not, it contains hidden system files, please do not interact with that partition.
Right click your Desktop and choose Disk Management
In Disk Management, find that System Reserved partition, right click that and chose 'Change drive letter, then click the button to remove the drive letter and apply that
The partition should then be hidden again.