Something I used to use when I was working on a desktop management system was similar to the following:

#!/usr/bin/perl

use strict;
use warnings;
use Win32::OLE 'in';
$Win32::OLE::Warn = 3;

my $server = shift;
my @users = ();

getLocalUsers($server,\@users);

print "Local User Accounts for $server:\n";

foreach( @users ) {
    print $_ . "\n";
}

# USE: getLocalUsers(<computer>,\@<list>)
sub getLocalUsers {
  my $strComputer = shift;
  my $users = shift;
  my $colAccounts = Win32::OLE->GetObject("WinNT://" . $strComputer);
  $colAccounts->{'Filter'} = ["user"];
  map { push @{$users}, $_->{'Name'}; } in $colAccounts;
}
[download]

The @users seemed to also include user accounts that current processes were running under. You could probably just filter them out.

Jeremy