problems understanding Authentication / Authorisation in ASP.NET 2.0.

[cmrchs]

hello,

I have problems understanding Authentication / Authorisation in
ASP.NET 2.0.

I have a simple WhoAmI.aspx page

protected void Page_Load(objec t sender, EventArgs e)
{
if (User.Identity. IsAuthenticated )
lblAuthenticati on.Text = "Authentica ted user: " +
User.Identity.N ame;
else
lblAuthenticati on.Text = "User not authenticated.
Anonymous access";

lblIdentity.Tex t = "Windows identity: " +
WindowsIdentity .GetCurrent().N ame;
} // Page_Load()
Settings in web.config are as follows:

<authenticati on mode="Windows" />
<identity impersonate="fa lse" />

<authorizatio n>
<allow users="*" />
</authorization>

IIS 7.0 has Anonymous Authentication enabled

I log in as Chris (administrator of the machine), and browsing to the
page the output is:

Authenticated user: MyPC\Chris
Windows identity: MyPC\Chris
Additionally checking for
_windowsPrincip al.IsInRole(Win dowsBuiltInRole .Administrator)
i get TRUE
Then, I create a new administrator user called 'Bob'
I am using Windows Vista Home Premium so I can switch to user Bob and
when browsing to the same page i get a completely different result
namely:

User not authenticated. Anonymous access
Windows identity: NT AUTHORITY\NETWO RK

how come???

Checking for
_windowsPrincip al.IsInRole(Win dowsBuiltInRole .Administrator)
i get FALSE ???

what is happening here?

thank you
Chris