Add “crypt32.dll” and “mpr.dll” to your dll_excludes. These are loaded by _ssl.pyd in newer versions of Python such as 2.7.11. But these libraries are Windows system libraries and OS version dependent, so they should not be packaged and distributed with your project. The Win7 “crypt32.dll” probably works on Win10, but the Win10 “crypt32.dll” most likely won’t work on Win7.