Download OpenVPN from here: http://openvpn.net/index.php/open-source/downloads.html.

Install by double clicking the downloaded executable. Once installed, copy the files below to C:\Program Files (x86)\OpenVPN\config\.

http://abc.cs.ndsu.nodak.edu/vpn/ca.crt

http://abc.cs.ndsu.nodak.edu/vpn/client.ovpn

Install OpenVPN through your distributions package manager.

Copy the files below to /etc/openvpn/

https://abc.cs.ndsu.nodak.edu/vpn/ca.crt

https://abc.cs.ndsu.nodak.edu/vpn/client.conf

Download Tunnelblick from https://code.google.com/p/tunnelblick/

Copy the files below and follow Tunnelblick installation instructions.

http://abc.cs.ndsu.nodak.edu/vpn/ca.crt

http://abc.cs.ndsu.nodak.edu/vpn/client.ovpn