After installing KB 973917, the IIS 6.0 application pools cannot start up

New issue on the block after installing KB 973917. Checking event viewer you would end up with

Event Type: Warning
Event Source: W3SVC
Event Category: None
Event ID: 1009
Date:  12/9/2009
Time:  10:55:01 AM
User:  N/A
Computer: WEBSERVER01
A process serving application pool 'DefaultAppPool' terminated unexpectedly. The process id was '9878'.
The process exit code was '0xffffffff'. 

To resolve this problem, reinstall Service Pack 2 for Windows Server 2003 on the web server.

Check out KB 


Before applying hotfix 973917 check whether it would break your IIS or not through this script

P.S: Script written by Punit Shah


Comments (8)

  1. Karl says:

    Yeah, this one hit us last night and broke IIS on one of our EV servers. Removing the patch resolves the issue.

  2. Doug says:

    Unbelieveable.  First an MS hotfix breaks OCS 2007 earlier this year, now this.  That’s it, I’ve stopped Automatic Updates on this box.  Ridiculous, Microsoft.

  3. Ken says:

    We had the same experience where all our application pools would fail  [Stopped Unspecified error] . With error A process serving application pool…with ‘0xffffffff’ in the even log. This happened on our test IIS servers prior to updates getting applied to our main production systems. I am uncertain as to the fate of our production systems.

    I have read several other threads about uninstalling 973917 or reinstalling SP2. Currently I have uninstalled 973917 and rebooted. This did not resolve the issue. (I then reinstalled 973917)

    I then moved on to downloading and am reinstalling SP2. Reinstalling SP2 resolved the issue.

  4. Jas says:


    As a best practise , Automatic update should be truned off on the production box


    it should be tested first on QA and if evrything goes well then install it on Prod.



  5. French says:

    I’ve removed update 973917.  This allowed the application pools to start again, but now I can’t login to OWA.  I enter my user name and password and it simply bounces me back to the login screen – a loop.  Any ideas?

  6. Jas says:

    Hello French,

    Haven’t noticed anything like this..

    Could please try with another user and see you are able to login?



  7. Alex says:

    We have the same exact issue. Found this:

     In the process of getting SP2 and re-applying it.

  8. Cory says:

    This issue is also caused by the brand new KB 982666. Same fix.

Skip to main content