use strict;
use warnings;

use Win32::GuiTest qw(:ALL);

system "start calc.exe";
sleep(1);
my @windows = FindWindowLike(undef, "Calculator");

my @children = GetChildWindows($windows[0]);
SetFocus($windows[0]);

foreach my $child (@children) {
   my $id = GetWindowID($child);
   my $class = GetClassName($child);
   print "child:  $id -- $class\n";
}

SendKeys("%{F4}");  # Alt-F4 to exit