Disable Loopback Check

Getting HTTP 401.1, Unauthorized: Logon Failed, or multiple login requests from a SharePoint site you're developing?  One simple solution is to disable the LSA loopback check in Windows.  This is a quick video that walks you through the necessary steps. 

Caution: Modifying the registry can cause serious problems with your machine, so it might be a good idea to backup your registry before making any changes.

Disable Loopback Check

1. Run the windows Registry Editor (regedit.exe) and navigate to the key: 
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa.
   
2. Right click Lsa and select New, then DWORD Value.
3. Enter DisableLoopbackCheck as the name and hit ENTER.
4. Double-click DisableLoopbackCheck and enter 1 as the Value data and click OK.
5. Reboot your machine for the change to take effect.