Output from psinfo -d on Win7 (current version from psinfo at 2015/11/22):
Physical memory: 3072 MB
Video driver: VMware SVGA 3D (Microsoft Corporation - WDDM)
Volume Type Format Label Size Free Free
A: Removable 0.0%
C: Fixed NTFS 99.90 GB 83.65 GB 83.7%
D: CD-ROM 0.0%
In do_df (disk.pm):
my @cols = split /\s+/, $_;
...
# if unit of total is GB then multiplicate 10241024
if ( $cols[6] eq "GB" ) { $total = $cols[5] * 1024 * 1024; }
if ( $cols[8] eq "GB" ) { $in_use = $total - ( $cols[7] * 1024 * 1024 ); }
=> The format is different today, so the hardcoded columns do not work