A few comments:
First, regarding your program's output. Proc::Killfam.pm has the following lines (14 and 15):

# We need Proc::ProcessTable to work properly.  If it's not available,
# then we act like Perl's builtin kill() command.
[download]

The first line of your output is simply an FYI warning. Thus, it is not the reason your program is not working. Rather, the second line

Can't call method "ExecuteCommand" on an undefined value at D:\...\exe
+c.pl line 1.
[download]

which has nothing to do with the first line, is why it fails. There is a coding error in the example you are trying to run. Since you haven't posted it, we cannot tell you what it might be.

Second, Proc::ProcessTable does work under Windows, but you need to have cygwin install. The following is from the Readme file bundled with the Proc::ProcessTable module:

"Please note that the windows port requires the Cygwin environment to work".

If you want cygwin, you can get it here

Third, from the Tk::ExecuteCommand manpage, the primary purpose of Tk::ExecuteCommand is to provide non-blocking program execution. Yet it still provides the functionality you want. That is, you can still use it if you want to redirect program output to a window. However, it will only work with output that typically goes to a console window (like the dos dir command). Try the following code (modified from the manpage):

use Tk;
use Tk::ExecuteCommand;

my $mw = MainWindow->new;
 $ec = $mw->ExecuteCommand(
     -command    => '',
     -entryWidth => 50,
     -height     => 10,
     -label      => '',
     -text       => 'Execute',
 )->pack;
 $ec->configure(-command => 'dir');
 $ec->execute_command;
 $ec->bell;
 $ec->update;

MainLoop;
[download]

Or, you can take that part of Tk::ExecuteCommand that handles the output redirection and use it as a basis for a custom-made solution.

davidj