Disk F:, therefore, would be the 4th disk added to your box.
But that depends on the user; you may not divide your disk into two disk spaces.
So, as I said, Disk F: would be the 4th disk in your setup.
Vladislav Mashirenko
Usually, that letter is assigned to an external drive you may connect to your setup.
How to find F: Drive on your setup?
Here, you will see all your drives.
Theyre located in the section Devices and drives.
Double-select your F: drive to open it and see the files stored on this drive.
After you click Properties, you will see the window with your drive configs.