The ActionLink method takes the arguments 'Text', 'Action', 'Controller'
Based on the parameters you have passed to it, it's looking for a method called contact
on your Home controller. If this method doesn't exist, you'll see the 404 error.
Make sure that the method exists on the controller. Also, check your casing, your controller method should really be
and you should change your ActionLink accordingly. e.g
Html.ActionLink("Contact", "Contact", "Home")