Back in MVC2 days I wrote a post on setting up a project with lowercase urls / redirecting and a workaround for IIS6. Luckily these days we have MVC4 which is a tad friendlier… to a degree.
In the Route collection registration area (Most likely in App_Start lest you've moved it) you can now simply add
routes.LowercaseUrls = true; (http://msdn.microsoft.com/en-us/library/system.web.routing.routecollection.lowercaseurls.aspx )
The big bugger about this is (and theres a bug in codepex for it here http://aspnetwebstack.codeplex.com/workitem/685?PendingVoteId=685) when you add an MVC Area the bloody thing stops working.
In which case you'll want to use http://nuget.org/packages/LowercaseRoutesMVC4/ which does the trick.