The Microsoft URL Rewrite Module 1.1 for IIS 7 provides flexible rules-based rewrite engine that can be used to perform broad spectrum of URL manipulation tasks, including, but not limited to:
Enabling user friendly and search engine friendly URL with dynamic web applications;
Rewriting URL’s based on HTTP headers and server variables;
Web site content handling;
Controlling access to web site content based on URL segments or request metadata.

The installation package includes several additional components and hotfixes required by URL rewriter. Refer to the KB articles for the hotfixes to get more details. In order to apply the hotfixes correctly without restarting the server, it is recommended that the WAS service is stopped before installing URL Rewrite Module. The following hotfixes will be installed with URL

Rewrite Module:
Update for IIS 7.0 FastCGI module (KB 954946);
Hotfix for IIS 7.0 SetUri function (KB 949172)
Hotfix for ASP.NET System.Web.dll (KB 957660)
Microsoft Visual C++ 2008 SP1 Redistributable Package