* To run openssl.exe, you must have the /ms4w/Apache/cgi-bin directory
  included in your PATH.

  * run /ms4w/setenv.bat to include this directory in your path,
    or set it in your Environment Variables on your machine
    
* also, at the same commandline, before executing openssl.exe, execute
  the following (modify for your correct path):
  
    set OPENSSL_CONF=c:\ms4w\tools\openssl\openssl.cnf

Documentation: https://www.openssl.org/docs/man1.0.2/

