Caveman's Blog

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IIS – Internal Server Error, Class not registered

with 6 comments

On one of the Win XP Professional machines IIS was throwing an Internal Server Error. When I checked the Event Viewer, there was a “Class not Registered” error and following was the content of the event:

Event Type: Warning
Event Source: W3SVC
Event Category: None
Event ID: 36
Description: The server failed to load application ‘/LM/W3SVC/1/ROOT. The error was ‘Class not registered’.

Bare bones: ASP and ASPX pages were not being recognised and http 500 error was returned to the browser.

I was able to google my way to the fix on Bernard’s MSMVP blog and God it made my day. Here is the working solution, its not my solution but I felt the need to document it and to share.

I was able to fix this issue following these steps:

1) Open Command Prompt and type “cd \windows\system32\inetsrv”
2) Run “msdtc -resetlog”
3) Run “rundll32 wamreg.dll, CreateIISPackage”
4) Run “regsvr32 asptxn.dll”
5) Run “iisreset”
6) Reboot…

1. The famous ‘Class not registered’ – Bernard’s MSMVP Blog


Written by cavemansblog

June 23, 2008 at 8:58 pm

Posted in IIS, Sudheer Reddy Battula

Tagged with , , ,

6 Responses

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  1. I having win2k3+Sp2 & getting error when i run “regsvr32 asptxn.dll”

    the error is
    “LoadLibrary(“asptxn.dll”)failed-The specified module could not be found.

    Pls help


    August 6, 2008 at 5:50 am

  2. Related Posts: (Has been very useful)

    Thanks Everyone.. I was also having the same issue.. Finally been able to get it solved.
    It did not work exactly as it’s mentioned on the top of the article.. but with experience of all of you i managed to get it done.
    Here’s what I did:
    1. To fix the error that’s coming when tried to open Component Services, I followed the instructions on KB:
    2. But it did not seem to have worked. Even after doing everything and restarting I was still getting the error.
    3. Uninstalled and Installed DTC:
    msdtc.exe –uninstall
    msdtc.exe –install
    This sorted out the error that was coming when the Component Services > Com+ Applications was opened.

    4. Installed Com+ Packages by:

    c:\windows\system32\inetsrv\>rundll32 wamreg.dll, CreateIISPackage
    c:\windows\system32\inetsrv\>regsvr32 asptxn.dll

    5. Restarted IIS: IISRESET
    So.. the approach is, first fix MSDTC, then com+, then restart IIS.


    December 17, 2008 at 12:44 pm

  3. cxrtsbvgdgkowasjwell, hi admin adn people nice forum indeed. how’s life? hope it’s introduce branch 😉


    December 30, 2008 at 12:39 am

  4. Perfect solution..Worked great for me.. 🙂 Thanks a ton.. 🙂


    February 18, 2013 at 7:07 am

  5. You helped me out!!! Many Thanks!!!

    Antuan Kouros

    September 11, 2014 at 1:37 am

  6. […] IIS – Internal Server Error, Class not registered … – Jun 23, 2008 · On one of the Win XP Professional machines IIS was throwing an Internal Server Error. When I checked the Event Viewer, there was a “Class not Registered …… […]

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