web forms password protect whole site

I am using asp.net 4.5 and have created a simple stock standard project by
File > New Project > Asp.net Web Application > Web Forms (Individual User Accounts) I try to password protect the whole site by adding the following to the Web.config within the `<system.web>` tag.
<authentication mode="Forms">
<forms loginUrl="Account/Login.aspx" name=".ASPXFORMSAUTH">
</forms>
</authentication>
<authorization>
<deny users="?" />
</authorization>
When I run the project now I get a strange error: There is a default Account folder which is added with the project. I know the login.aspx is there and works.
 
HTTP Error 404.15 - Not Found Requested URL http://localhost:51673/Account/Login?ReturnUrl=%2FAccount%2FLo ...