NOTE - the downloadable files sourced from OpenSSL.org only work with Linux!!! In order to install on Windows 10, you must with compile the binaries yourself OR find a compiled version already on the web. The instructions below will only talk about finding a website with a compiled version of OpenSSL.
Copied directly from the website: (https://www.cloudinsidr.com/content/how-to-install-the-most-recent-version-of-openssl-on-windows-10-in-64-bit/) If the website goes down please review this confluence page with the site copied off on 1/23/2018. OpenSSL - Installation