use Win32::Process::Info;
Win32::Process::Info->Set (variant => 'WMI');
my $pi = Win32::Process::Info->new();
for ( $pi->ListPids )
{
    my ($info) = $pi->GetProcInfo ($_);
    if ($info->{Name} =~ /notepad/gi ) {
    $pid =  $info->{ProcessId};
    push @pids, $pid;
    }
}
print "@pids";