Download the latest Open VPN installer from the Open VPN downloads page. Ensure that you download the correct version for your Windows XP architecture i.e. 32 or 64 bit (If you're not sure what's your Windows architecture click here).
Run the Open VPN installer by double clicking on it and answer the required prompts to install the Open VPN. Select the default set of components to install. If you have not installed Open VPN before you may be asked to install the TAP drivers. Check the box "Always trust software from Open VPN" and click Install.
Download the Open VPN configuration files, extract the zip file and copy the *.ovpn files to the config folder within the Open VPN installation directory (Usually C:\Program Files (x86)\OpenVPN\config on 32 bit systems and C:\Program Files\OpenVPN\config on 64 bit systems).
Start the Open VPN GUI by double clicking the shortcut on the desktop.
Right click on the Open VPN system tray icon (two small monitors in bottom right corner, click the up arrow if icon is hidden) and select the server you want to connect to and click Connect. Enter your username and password when prompted.
When the tray icon turns green you are connected to the ServStrong VPN service. Right click on the Open VPN system tray icon, Select the server you are connected now and click on disconnect.