When you say it doesn't show you anything, do you mean there is literally nothing at all? What you should see when you choose to filter by filename is the hard disks names. The attached shows my two hard disks.
Don't forget the obligatory/regens/reboots/patience.
If all else fails, in the past I have just removed the hard drive in My Devices in web admin, reboot, and start again (hard drive should be re-detected).
FYI I have only over used "Use LMCE structure", so don't know if this applies to selecting "make all content public".