WP RC1 on windows server (htaccess problem)

I want to use multisite feature of wordpress RC1. My problem is that my server is windows server and it can’t use .htaccess file. As you know for enabling multisite feature, this file is necessary. My .htaccess file content is :
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule . index.php [L]

please help me. How can I use this feature??