Moving from MVC 3 to MVC 4 read on. There are a number of references that need updating as well as update to the web.config(s). [More]
Scenario: I deployed my mvc 3 application to IIS 6 (with NTLM authentication). While using Internet Explorer (IE) everything looked great. When I tested the site with other common browsers Chrome/FireFox/Safari none of the styles specified in the css sheet were used [More]
Are you running in IIS7 integrated mode?
Classic mode of IIS7 does not automatically map extensionless URLs to ASP.NET (much like IIS6).
Also make sure your Web.config <system.webServer> tag is configured correctly.
<system.webServer> <validation validateIntegratedModeConfiguration="false"/> <modules runAllManagedModulesForAllRequests="true"/></system.webServer>
On my workstation windows 7, 64 bit I had set my app pool to classic and added a "Wildcard Script Map" to C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll (32bit dll). The end result was my web.confi webServer section looked like
<system.webServer> <validation validateIntegratedModeConfiguration="false" /> <modules runAllManagedModulesForAllRequests="true" /> <handlers> <add name="_wildcard 32" path="*" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" resourceType="Unspecified" requireAccess="None" preCondition="classicMode,runtimeVersionv4.0,bitness32" /> </handlers> </system.webServer>