Note: This article was originally published in 2013. Some steps, commands, or software versions may have changed. Check the current Exchange 2010 documentation for the latest information.

In this step-by-step guide, you’ll learn remove error . Microsoft Exchange Server 2010 brought improvements in high availability with Database Availability Groups (DAGs), role-based access control, and enhanced Outlook Web App.

Prerequisites

Before you begin, make sure you have:

  • Exchange Server 2010 SP3 or later
  • Exchange Management Console or Exchange Management Shell access
  • Appropriate administrative permissions

How to: Remove error “Error 503 - Service Unavailable” after removing (http://www.microsoft.com/exchange “Microsoft Exchange Server”) 2013 on (http://www.iis.net/ “Internet Information Services”)

Okay, so I am guilty of many bad practices like not backing up a (http://en.wikipedia.org/wiki/RAID “RAID”) before expanding it, and as of late, using a server box that had Exchange Server 2013 for other purposes instead of reinstalling. To my defense, (http://www.microsoft.com “Microsoft”) automatic key activation is a pain, as I am reinstalling a server and they count that against my server quota and then if I reinstall too much too often I need to give them a call to activate… so I decided simply (http://en.wikipedia.org/wiki/Uninstaller “Uninstaller”) Exchange 2013 would suffice… no comment. My recommendation and (http://en.wikipedia.org/wiki/Best_practice “Best practice”) is to wipe that server clean and repurpose it. Anyway, getting back on track if you uninstalled Exchange 2013, installed a bunch of other things and now you are enjoying a bunch of left over Exchange goodies like this “Error 503 - Service Unavailable” in IIS, welcome to my world.

The Cause

You installed Exchange 2013, and when removed it doesn’t do a good clean up job. As you can see in IIS there are a bunch of app pools from your server’s Exchange days and the inner configs of IIS are also full of them. The issue on this particular problem is the following which you can observe on your Event Viewer: Log Name: Application Source: (http://www.microsoft.com/WINDOWS “Windows”)-IIS-W3SVC-WP Date: 09/03/2013 03:55:23 p. m. (http://en.wikipedia.org/wiki/Event_Viewer “Event Viewer”): 2280 Task Category: None Level: Error Keywords: Classic User: N/A Computer: SomeServerName Description: The Module (http://en.wikipedia.org/wiki/Dynamic-link_library “Dynamic-link library”) C:Program FilesMicrosoftExchange ServerV15Binkerbauth.dll failed to load. The data is the error. Event Xml: xmlns=“http://schemas.microsoft.com/win/2004/08/events/event”> 2280 0 2 0 0 0x80000000000000 41566 Application SomeComputerNAme C:Program FilesMicrosoftExchange ServerV15Binkerbauth.dll 7E000000

The solution:

Take a look at: C:WindowsSystem32inetsrvconfigapplicationHost.config there you will find a line that reads like so:

< add name=”kerbauth” image=”C:Exchange ServerV15Binkerbauth.dll” />

At this point if you stop IIS, edit the file as an administrator and remove that line your problem will be solved. A word of caution to this tale, if you keep exploring the file you will see that Exchange references are all over the place and probably you will need to add a Kerberos Authentication DLL to replace that entry if you have an application that has been set up to use Kerberos. My advice: IF you can use another server and wipe this one clean… I have no clue what other issues you may encounter because of the poorly uninstalled Exchange Server. Rumor has it this happens on Exchange Server 2010 as well…  

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Summary

You’ve successfully learned remove error . If you run into any issues, double-check the prerequisites and ensure your Exchange 2010 environment is properly configured.