Login as Administrator via RDP or VNC
Open PowerShell
Run the command > diskpart
Once diskpart starts, type the command DISKPART> list volume
Note the number of the volume that is not being reported correctly then run the command (replacing the # with the number of the volume) DISKPART > select volume #
Next, run the command DISKPART > extend filesystem
That's it, your disk space should now be reported back to you correctly. If you have My Computer open, you may need to refresh the screen to see the proper size.
