Turn off Local Loopback feature
A litle time ago I created a new SharePoint 2010 Web Application. For the hostheader I typed in custom name: intranet. At the root I created a team site. When I tried to access the site collection on http://intranet, I got a HTTP 401.1 - Unauthorized.
This is because Windows Server 2008 and 2003 have a Local Loopback feature turned on by default. You can turn this feature off in the registry:
- Click Start, click Run, type regedit, and then click OK.
- In Registry Editor, locate and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
- Right-click Lsa, point to New, and then click DWORD Value.
- Type DisableLoopbackCheck, and then press ENTER.
- Right-click DisableLoopbackCheck, and then click Modify.
- In the Value data box, type 1, and then click OK.
- Quit Registry Editor, and then restart your computer.
Read more about it in the following Microsoft’s knowledge base article:
http://support.microsoft.com/kb/896861