Download OpenSSL for windows here: https://www.softpedia.com/get/Programming/Components-Libraries/OpenSSL.shtml Then run in cmd: C:\> \path\to\vcvarsall.bat x86_amd64 C:\> set LIB=C:\OpenSSL-win64\lib;%LIB% C:\> set INCLUDE=C:\OpenSSL-win64\include;%INCLUDE% C:\> pip install cryptography https://community.home-assistant.io/t/windows-10-failed-building-wheel-for-cryptography/233257 Variable Name: HomeAssistant 1 Varriable Value: C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\VC\Auxiliary\Build\vcvarsall.bat x86_amd64 Variable Name: HomeAssistant 2 Variable Value: C:\> set LIB=C:\Program Files\OpenSSL-Win64\lib;%LIB% Variable Name: HomeAssistant 3 Variable Value: C:\> set INCLUDE=C:\Program Files\OpenSSL-Win64\include;%INCLUDE% Variable Name: HomeAssistant 4 Variable Value: C:\> pip install cryptography