You execute a Python program that uses a module and the module throws up this error at runtime:
ImportError: DLL load failed: %1 is not a valid Win32 application.
This is usually caused by a mismatch in the DLL of the module. I faced this error when I had mistakenly installed a 32-bit Python module (numpy in this case) on to a 64-bit Python installation. The error is thrown when the communication between the 64-bit Python and the 32-bit module DLL does not work, as expected. The error went away after I installed a 64-bit version of the module.
Tried with: Python 3.2 64-bit on Windows 7