How to use ISAPI_Rewrite 3 with Drupal

Drupal + ISAPI_Rewrite

Introduction

Drupal is a very popular CMS (Content Management System) that supports SE-friendly URLs. It is designed for usage with Apache Web Server and has no default solution to use with IIS. But of course you can use this CMS with IIS Web Server and ISAPI_Rewrite will help you to enable SE-friendly URLs. This short article describes how to setup Drupal to use with ISAPI_Rewrite 3.
In this article we suppose you already have IIS and ISAPI_Rewrite 3 installed. To write the article we have used ISAPI_Rewrite 3.1.0.56 and Drupal 6.4.

Getting and Installing Drupal

You can download Drupal from official web site: http://drupal.org/. Please install Drupal according to installation instructions provided by vendor.

Please note! In the installation wizard you can see the configuration for enabling SE-friendly URLs, but with IIS you can't use it because Drupal blocks controls as shown on this picture:

Picture 1. Configuration for SEO-friendly URLs during installation.

Please just leave it as is, it is possible to change this setting later.

Enabling SEO-friendly URLs

Please find the file %PATH_TO_DRUPAL%/sites/default/settings.php, where %PATH_TO_DRUPAL% is the root of Drupal's installation folder. Open this document and append the code given below: 

$conf[ 'clean_url' ] = 1;

Then please open .htaccess file located in the root folder of Drupal. There are many rules but only some of them are intended for ISAPI_Rewrite, others are for Apache Web Server.
Please remove all rules from .htaccess file and put these: 

RewriteEngine on

# Modify the RewriteBase if you are using Drupal in a subdirectory or in a
# VirtualDocumentRoot and the rewrite rules are not working properly.
# For example if your site is at http://example.com/drupal uncomment and
# modify the following line:
# RewriteBase /drupal
#
# If your site is running in a VirtualDocumentRoot at http://example.com/,
# uncomment the following line:
# RewriteBase /

# Rewrite URLs of the form 'x' to the form 'index.php?q=x'.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]

Actually these are default Drupal rules for Apache mod_rewrite configuration and we just cut them from default .htaccess file.

Done! Now you can use Drupal CMS with pretty SEO-friendly URLs.