Interop.ComAdmin exception when using IIS on a 64-bit OS

If you install IIS on a 64-bit operating system, you may get the following error when navigating to your website locally:

Could not load file or assembly ‘Interop.COMAdmin’ or one of its dependencies. An attempt was made to load a program with an incorrect format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.BadImageFormatException: Could not load file or assembly ‘Interop.COMAdmin’ or one of its dependencies. An attempt was made to load a program with an incorrect format.

The clue here is the BadImageFormatException, which hints that this is a 32/64 bit issue. To fix it, in IIS Services Manager, go to Application Pools, select the application pool under which your website/application is running, and choose ‘Advanced Settings’. Change ‘Enable 32-bit Applications’ from False (the default) to True. Recycle your app pool, and reload your browser page, no more error!