Errors Running ASP.NET 1.1 on IIS7 (applicationHost.config)


I am trying to port an existing ASP.Net 1.1 website to another web server that currently runs IIS7 and a number of websites that target either .Net 2.0, 3.5 or 4.0. All other sites continue to work perfectly. Unfortunately, I can only browse static files on the newly imported site. If I try to access any of the Features in IIS7 for the new site I get the following error dialog:

There was an error while performing
this operation.





I followed the instructions on this page but am at a loss as to how to get this working.

Best Solution

I encountered this problem too this afternoon.

I did a quick google and found others with the same issue on the forum. The issue seemed to be that

Here is what got me past this error, hope it works for you.

the runtime tries to load the corresponding configuration, it doesn't take the bitness of the application pool into the consideration. As you know, ASP.NET 1.1 is only supported on 32-bit. So if you have a 64-bit OS, in order to run ASP.NET 1.1, you have to enable 32-bit applications in the application pool. So, with the QFE/SP2 on 64-bit OS (and only on 64-bit OS), the runtime is incorrectly looking for the 1.1 version of the configuration under Framework64, which does not exist.


  1. Create the Framework64 directory for 1.1 md \windows\\framework64\v1.1.4322\config\
  2. Copy the 32bit config to 64bit config location created in step 1. copy \windows\\framework\v1.1.4322\config\machine.config \windows\\framework64\v1.1.4322\config\