I upgraded my development machine to 64-bit Win7, and now when I try to connect to a local ASP.Net project I get:
HTTP Error 500 …
Calling LoadLibraryEx on ISAPI filter "C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_filter.dll" failed
There are several puzzling things about this; the ASP.Net project was a .Net 2.0 ASMX so it was using C:\Windows\Microsoft.NET\Framework\v2.0.50727. If it updated to x64 without asking me, should it not use C:\Windows\Microsoft.NET\Framework64\v2.0.50727\? Where is C:\Windows\Microsoft.NET\Framework\v4.0.30319\ coming from?
I opened IIS Manager and the selected .Net Framework version for my machine is 2.0.50727. Framework version for my default application pool is the same.
I am developing in VS2008, which does not even have an option for targeting .Net 4.0.
Best Answer
It sounds to me like you have a 32 bit part of your application, and your trying to run it in a 64bit application pool in IIS. By default the application pool is 64bit on a 64bit OS. To enable 32bit mode you need to go to the advanced properties of the application pool and change the setting for "Enable 32 Bit Applications".