iis 7 disable windows auth

I setup a test website on my IIS 7.5, I created a Web Application project in VisualStudio and set up a web site in a new application pool in Classic Pipeline Mode.

I have this line in C:\Windows\System32\drivers开发者_JAVA百科\etc\hosts:

192.168.50.142     dev.mybigdomain.org.uk

Now if I access my website with http://localhost/testHello/Default.aspx it works fine, but when I try http://dev.mybigdomain.org.uk/testHello/Default.aspx I get a "Windows security" window asking for authentication, but if enter "administrator" and password it does not recognise them and just asks again.

How can I disable the authentication?

Have you try to change the web.config authentication mode to Forms or None?

 <system.web>
...
 <authentication mode="Forms">

instead of

<system.web>
...
<authentication mode="Windows">