Plaincart system problem install and login to admin section. Please help

hi everybody
i downloaded and install to localhost the PLAINCART system http://www.phpwebcommerce.com/

url is
http://localhost/www.olympic-armatura.com.pl/index.php

base dir is
c:/usr/serwis/www/www.olympic-armatura.com.pl/

and a have problem to enter admin section. When i click to admin/index.php
i have error 404. In error log is text

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[Fri May 05 17:29:29 2006] [error] [client 127.0.0.1] File does not exist: c:/usr/serwis/www/www.olympic-armatura.com.pl/admin/www.olympic-armatura.com.pl/admin/login.php
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probable is error in library/config.php file

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$thisFile = str_replace('\', '/', __FILE__);
$docRoot = $_SERVER['DOCUMENT_ROOT'];

$webRoot = str_replace(array($docRoot, 'library/config.php'), '', $thisFile);
$srvRoot = str_replace('library/config.php', '', $thisFile);

define('WEB_ROOT', $webRoot);
define('SRV_ROOT', $srvRoot);
//////////////

please help !