I don't think windows OSes have "root" directories/folders.
You might have to determine what drives are available
and iterate over those ...

@drives = &someSubThatReturnsListODrives();
foreach my $drive ( @drives ) {
      find(\&handleFind, $drive);
}

sub handleFind {
      my $foundFile = $File::Find::name if 'VCVARS32.BAT';
      print "$foundFile\n";
}
[download]

... or something like that. I hope someone comes up with a better answer for you. :)