“An attempt was made to load a program with an incorrect format” even when the platforms are the same

Question

I\'m calling functions from a 32-bit unmanaged DLL on a 64-bit system. What I get is:

BadImageFormatException: An attempt was made to load a program w

Answer 1

1:Go to: Tools > Options > Projects and Solutions > Web Projects > Use the 64 bit version of IIS Express 2: change below setting for web service project.