http://support.microsoft.com/?id=896861

You can test this by attemtping to access the server in the following way:

https://netbiosname/Autodiscover/Autodiscover.xml :
It will prompt for credentials. After prompting a couple of times we get the following error:Error: Access is Denied.-

Use https://localhost/Autodiscover/Autodiscover.xml :
It will work fine and give an output.

DisableLoopbackCheck can be disabled but then the system is left open to an attack and I would not recommend disabling this function unless you will enable once testing is completed.

: Disable the loopback check
Follow these steps:
1.Click Start, click Run, type regedit, and then click OK.
2.In Registry Editor, locate and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
3.Right-click Lsa, point to New, and then click DWORD Value.
4.Type DisableLoopbackCheck, and then press ENTER.
5.Right-click DisableLoopbackCheck, and then click Modify.
6.In the Value data box, type 1, and then click OK.
7.Quit Registry Editor, and then restart your computer.