SharePoint disable loopback check (DisableLoopbackCheck dword in registry)

Ive found this very handy.. recently, I was working on a server and we were trying to access the local SharePoint site http://127.0.0.1 or http://nameoflocalserver/pages/default.aspx and I was constantly prompted for the username and password. In SharePoint 2010, it can really annoy you by not accepting your username password credentials in the popup window.

Its a ‘feature’ on the server that you need to disable as a workaround (if you are an Admin/Developer) on a DEVELOPMENT and PREPROD environment. Caution: Microsoft Best practices is out of scope in this article. Do your own research on this topic.

There are two methods to do this: 1.  Specify the host names in the registry – BackConnectionHostNames (more secure and recommended for PRODUCTION servers). Refer http://support.microsoft.com/kb/896861 2. Disable the loopback check – DisableLoopbackCheck (less secure and recommended for DEVELOPMENT environments). Read on to use this method 2 and add via an easy powershell cmd.

You would need to create a DWORD registry key in the registry called DisableLoopbackCheck and set it to 1. Follow these steps:

Option 1: Add this registry entry by PowerShell

New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name “DisableLoopbackCheck” -value 1

Option 2: Add this registry entry manually

Click Start, click Run, type regedit, and then click OK In Registry Editor, locate the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa Right-click Lsa, point to New, and then click DWORD Value. (In Win 2008, its DWORD 32bit) 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. You may need to restart your server.

For more information about this, click the following article number to view the article in the Microsoft Knowledge Base: 281308 (http://support.microsoft.com/kb/281308/ ) Connecting to SMB share on a Windows 2000-based computer or a Windows Server 2003-based computer may not work with an alias name.