#!c:/perl/bin/perl -w
$|++;

use strict;
use Win32::API;

sub MONITOR_ON () { -1 }
sub MONITOR_STANDBY () { 1 }
sub MONITOR_OFF () { 2 }

Win32::API->Import('user32', 'SendMessageA', 'NNNN', 'N'); 
Win32::API->Import('user32', 'FindWindowA', 'PP', 'N');

my $hwnd = FindWindowA('Shell_TrayWnd', 0);

SendMessageA($hwnd, 0x112, 0xF170, MONITOR_STANDBY);
sleep 6;
SendMessageA($hwnd, 0x112, 0xF170, MONITOR_OFF);
sleep 6;
SendMessageA($hwnd, 0x112, 0xF170, MONITOR_ON);