Set “pageExtension” to nothing to tell SiteFInity to use Extension less URLs.
The line to change looks like this:
<cms defaultProvider="Sitefinity" pageExtension=".aspx" disabled="false" pageEditorUIMode="Overlay">
Change it so that the pageExtension property is empty liek this:
pageExtension=""Note: The FormsAthentication and RoleManager modules are not available for extensionless request but you need them for the admin section of Sitefinity.
To enable FormsAthentication and RoleManager add the runAllManagedModulesForAllRequests property to the modules section of the Web.Config file.
E.G.
<modules runAllManagedModulesForAllRequests="true">Now you should have Extension less URLs in Sitefinity.