New SharePoint website keep asking for user credentials - Windows Loopback Check

One of the very first thing people are challenged with, after preparing a new machine with Windows Server 2003 SP1 or Windows Server 2008 for deploying SharePoint is the Loopback check. In Bob Fox's words, "The feature prevents access to a web application using a fully qualified domain name (FQDN) if an attempt to access it takes place from a machine that hosts that application. The end result is a 401.1 Access Denied from the web server and a logon failure in the event log. Unfortunately 401.1 is not really helpful as this error code means there is a problem with the user credentials". This KB article from MS details the issue a bit more.

One simple solution to fix the issue is to run the following Powershell script, Job done!!!

1	New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name "DisableLoopbackCheck" -value "1" -PropertyType dword