SharePoint 2013 Keeps Prompting For Credentials (DisableLoopbackCheck - BackConnectionHostNames - Logon Failure 401.1 - Access Denied )

Problem:

When you access a SharePoint site collection, it keeps on prompting for authentication and eventually give you an Access Denied error.

Reason:

This is a feature that 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.

Solution:

There are 2 ways to solve this, (1) the correct way and (2) the fast and easy way.

1 - The correct way (test/production servers): 
Specify the host names that needs to do loop back check in the registry – BackConnectionHostNames. This is the correct way and is more secure. http://support.microsoft.com/kb/896861
 - Open regedit.exe
 - Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
 - Create a new multi-string value and name it "BackConnectionHostNames"
 - Type the host name of site that are referencing on the local server 
   (multiple host names must be separated by a newline)
 - Click OK and close regedit
 - You should no longer get the 401.1 Access Denied message (you may also need to restart the IISAdmin service)

1 - The easy way (development servers): 
Disable the loopback check (DisableLoopbackCheck) altogether. This puts your server in a security risk. http://support.microsoft.com/kb/896861
 - Open regedit.exe
 - Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
 - Create a new d-word (32-bit) and name it "DisableLoopbackCheck"
 - Edit the d-word and give it a value of 1
 - Click OK and close regedit
 - You should no longer get the 401.1 Access Denied message (you may also need to restart the IISAdmin service)

Additional info:

The event view might also give the following error.
Event Type: Failure Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 537
Date: Date
Time: Time
User: NT AUTHORITY\SYSTEM
Computer: Computer_Name
Description: Logon Failure:
Reason: An error occurred during logon
User Name: User_Name
Domain: Domain_Name
Logon Type: 3
Logon Process: Ðùº
Authentication Package: NTLM
Workstation Name: Computer_Name
Status code: 0xC000006D
Substatus code: 0x0
Caller User Name: -
Caller Domain: -
Caller Logon ID: -
Caller Process ID: -
Transited Services: -
Source Network Address: IP_Address
Source Port: Port_Number