Trying to create an API controller but getting 404 error when accessing URL

public class CustomController : UmbracoApiController

{

[System.Web.Http.HttpGet]
public IEnumerable<string> GetAllProducts()
{
return new [] {"Table", "Chair"};
}

}

I thought I could then access the URL using /umbraco/api/Custom/GetAllProducts but get 404.

Also have same issue with surface controllers, for example;

public class LoginController : SurfaceController

{

[System.Web.Http.HttpGet]
public int Index()
{
return 1;
}

}

/umbraco/surface/Login/Index gives me a 404.

I am surely missing something simple here, it's been one of those days, so any clues would be really appreciated. Tried running in IIS Express and IIS same issue, surely a config thing, I have the training site I did in training (v 7.0.4) which is working ok? I understand I shouldn't need to create any custom routes or anything like that?

Version 7.1.2