Download Df.exe to display information about the drive letters in your computer.

When you type df /?, the program displays:

usage: df \[-c -b -f|-F -r|-R -w|-W  \[drive ...\]                              -f : include floppy disks                              -F : do only floppy disks (local only)                              -c : include CD-ROMs                              -r : exclude remote disks                              -R : do only remote disks                              -b : (bare display) no header or footer or totals                              -w : display output in a Windows Messagebox                              Copyright 1996, 1998, 2000 by Paul R. Sadowski .                              All Rights Reserved. Licensed for noncommercial use.
When I ran df -r, I received:
drive  kbytes        used       avail capacity                              C:\  45090983    14530740    30560243    32%    \[Volume has no label\] (ntfs)                              D:\  27661615    10114359    17547255    37%    BACKUP (ntfs)                              H:\    103198         359      102838     0%    \[Volume has no label\] (ntfs)                              ------------------------------------------------------                                   72855796    24645458    48210336    33%
When I ran df -b -r, I received:
C:\  45090983    14530740    30560243    32%    \[Volume has no label\] (ntfs)                              D:\  27661615    10114359    17547255    37%    BACKUP (ntfs)                              H:\    103198         359      102838     0%    \[Volume has no label\] (ntfs)
NOTE: If you include floppy disks, you will get a pop-up window that you must respond to, unless there is media in the drive.