Although you may want to use File::Find as other respondents suggested, you can get your subroutine to work by declaring your variables with "my" inside your subroutine Recurse.
#!wperl

use strict;
use Win32;
sub Recurse;

Recurse ($ARGV[0]);

sub Recurse
{
  my ($DirItem);
  my ($Formatted);
  my ($PWD);

($PWD) = @_;

opendir(DIR, $PWD);
    my @DirList = readdir(DIR);
closedir DIR;
foreach $DirItem (@DirList)
    {
    $Formatted = $DirItem . "z";
    if ( -d $DirItem &&$DirItem ne "." && $DirItem ne "..")
    {
    &Recurse ($PWD . "\\" . $DirItem);
    }
    if ($DirItem ne "." && $DirItem ne "..")
        {
           rename("$PWD\\$DirItem","$PWD\\$Formatted");
       }    
    }
}

[download]
Updated: Changed
  rename($DirItem,$Formatted);
to 
  rename("$PWD\\$DirItem","$PWD\\$Formatted");

That should fix it.

In reply to Re: Directory recursion on win32 by Thelonius
in thread Directory recursion on win32 by fourmi

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