On Windows:
1. Uninstall the VPN.AC client software from Programs & Features
2. Open Control Panel\Network and Internet\Network Connections and delete the VpnAc network interface.
If you also wish to remove the Tun/Tap driver, open Control Panel\Programs\Programs and Features and remove the Tap-Windows software.
3. If the option 'Launch on system start' wasn't disabled in the VPN client software before uninstall, open the Task Scheduler and remove the 'vpn.ac autostart' from the Task Scheduler Library
2. Delete the folder where you extracted our client software.
On Mac OS X:
Open Finder > Applications and scroll down to find the VPN.AC Client Software. Drag & drop it to the Trash.