SharePoint Disable Loopback on server

This needs to be actioned to resolve 401 errors (access denied from Web Server and putting a logon failure in eventlog)




Setting the DisableLoopbackCheck registry entry in the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa registry subkey to 1. 


To set the DisableLoopbackCheck registry entry to 1, follow these steps on the client computer: 


1. Click Start, click Run, type regedit, and then click OK.  
2. Locate and then click the following registry subkey: 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. Exit Registry Editor. 
8. Restart the computer. 


Note You must restart the server for this change to take effect.