Download OpenVPN Windows Client from (32-bit Windows) or from (64-bit Windows).
Open the downloaded file to begin the installation.
Click "I Agree".
Uncheck "Show Readme" and Click "Finish".
Now go to the config files which you downloaded in step 1. Extract them, copy them and paste in C:\Program Files\OpenVPN\config. Or you can simply drag and drop them.
Now, click on OpenVPN GUI shortcut on your desktop to run it.
You will find OpenVPN GUI icon on the taskbar at the bottom right of your screen.
Right click on it, select your desired server and click ‘Connect’.
Enter your username and password provided by OneVPN and click "OK"
Connection will be established after a few seconds and OpenVPN GUI icon will go green like this which represents a successful connection.
How to Disconnect/ Change Server
When you need to disconnect, right click on OpenVPN GUI icon on task bar, select the server which is connected and click ‘Disconnect’.Similarly, you can connect to any other server, but after disconnecting to the previous one.