Joomla 4/5 User Manual
Enabling Search Engine Friendly (SEF) URLs on IIS/IIS7
If you have a server running IIS 7 and PHP, you can take advantage of IIS's own internal URL rewriting by using a web.config file similar to the one listed below.
You can create the file yourself or use the GUI in the IIS7 Manager. You can import .htaccess rules using the GUI/wizard.
This functionality depends on the presence of the IIS URL Rewrite Module, which does not come with Windows. It is a free download and a Microsoft product.
If the IIS URL Rewrite module is installed, your website manager will have a tool for "URL Rewrite", visible in the IIS Manager's view of your site's configurable IIS modules. The interface is largely self-explanatory. Regular expressions, wildcards or exact matches are all supported.
In the Joomla config turn on both the SEF and Apache mod_rewrite, next create a rule under IIS URL Rewrite:
Pattern field: ^([^/]+)/?$
Ignore case ON
Action type: Rewrite
Rewrite URL: index.php/
This has been tested on Joomla 1.5 with IIS 7 on Windows Server 2008 with no problems so far. For more information on converting .htaccess to web.config, check out http://learn.iis.net/page.aspx/557/translate-htaccess-content-to-iis-webconfig/