use Win32::TieRegistry( Delimiter=>"/" );
sub get_sp {
    my $cpu= shift @_;
    my $ver= $Registry->{"//$cpu/LMachine/Software/"
      . "Microsoft/Windows NT/CurrentVersion//CSDVersion"};
    if(  ! $ver  ||  $ver !~ /(\d+)/  ) {
        return "unknown";
    }
    return $1;
}