my $ver_str = `ver`;

   # Test strings
   # my $ver_str = 'Windows 98 [Version 4.10.1998]';
   # my $ver_str = 'Microsoft Windows 2000 [Version 5.00.2195]';
   # my $ver_str = 'Microsoft Windows 95. [Version 4.00.1111]';
   ## guessed on this one ##  my $ver_str = 'Windows NT Version 3.51';
   # my $ver_str = 'Windows NT Version 4.0';

print "VER: $ver_str\n";
$_ = $ver_str;
my $os_ver = "N/A";
$os_ver = 'win95' if m/( 95 | 95. )/;
$os_ver = 'win98' if m/ 98 /;
$os_ver = 'nt351' if m/ NT / && m/ 3.51/;
$os_ver = 'nt40'  if m/ NT / && m/ 4.0/;
$os_ver = 'win2k' if m/ 2000 /;
print "\$os_ver: $os_ver\n\n";