Make sure the run time variable OPENSSL_CONF is set.
set OPENSSL_CONF=C:\Program Files\Apache Software Foundation\Apache2.4\conf\openssl.cnf
In the httpd.conf you would need some extra line (remove the # if it's there):
LoadModule ssl_module modules/mod_ssl.so
and
Include conf/extra/httpd-ssl.conf
Be sure you have created your OpenSSL certificate when you will edit the httpd-ssl.conf file.
Extra step for the certificate
openssl req -new -out server.csr
openssl rsa -in privkey.pem -out server.key
openssl x509 -in server.csr -out server.cert -req -signkey server.key -days 365
And you move the server.key and server.cert to the conf folder. (C:\Program Files\Apache Software Foundation\Apache2.4\conf)