This exception will occur if you have a 64-bit program calling our 32-bit DLL. This will only happen if you are running on a 64-bit operating system.

As a rule 32-bit programs must call 32-bit DLLs and 64-bit programs must call 64-bit DLLs. However, if you use Visual Studio 2005 and are using either C# or VB then the default configuration is for your program to be 32-bit under 32-bit Windows and 64-bit under 64-bit Windows. In this case if you are calling dd32.dll it will fail under 64-bit Windows with the BadImageFormatException exception.

To solve this problem you must create your program to be 32-bit. This will then work under both 32-bit and 64-bit Windows. To do this using Visual Studio 2005 choose Project Settings | Build | Target Platform and change it from "Any" to "x86".