The default web.config file for vBulletin. IIS uses web.config along with the URL Rewrite Module to handle rewrites for vBulletin.

<?xml version="1.0" encoding="UTF-8"?>
<!-- This file is to support redirection in IIS.
This file is harmless if you are running under Apache -->
                <clear /> <!-- reset other rewrite rules -->
                <rule name="Css" stopProcessing="true">
                    <match url="^css.php$" ignoreCase="false" />
                    <action type="Rewrite" url="core/css.php" />

                <rule name="Installer" stopProcessing="true">
                    <match url="^install/" ignoreCase="true" />
                    <action type="Rewrite" url="core/install/" />

                <rule name="Main Redirect" stopProcessing="true">
                    <match url="^(.*)$" ignoreCase="false" />
                    <conditions logicalGrouping="MatchAll">
                        <add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
                        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />

                    <action type="Rewrite" url="index.php?routestring={R:1}" />

                <rule name="Admincp" stopProcessing="true">
                    <match url="^(admincp/)$" ignoreCase="false" />
                    <action type="Rewrite" url="index.php?routestring={R:1}" />