401 error occurred on server Windows logon

Method 1:disable the loopback check
The first method is to disable the loopback check by setting the DisableLoopbackCheck registry key.
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.

401 error occurred on server Windows logon