This problem occurs when any one of the following conditions is true:
- You are using the 32-bit version of IIS Manager on a 64-bit computer.
- You are using IIS in Microsoft Windows-32-on-Windows-64 (WOW64) mode.
- You have set the Enable32bitAppOnWin64 property to True in IIS. This setting lets IIS run in 32-bit mode on a 64-bit computer.
This problem can also occur because the 64-bit version of IIS Manager cannot load the 32-bit Aspnet_isapi.dll file as a native 64-bit file. Additionally, the 64-bit version of IIS Manager cannot load this file in WOW64 32-bit mode.
Article ID: 919283 - Last Review: Jun 29, 2011 - Revision: 1