TAP-Win32 driver installation procedure

1. Download OpenVPN package for Windows (version 1.6 or later)
   (OpenVPN package contains TAP-Win32 Virtual Ethernet Adapter driver)
2. Execute the openvpn installer (openvpn-1.6-install.exe)
3. select "TAP-Win32 Virtual Ethernet Adapter"
   (you may select other components, if you want)
4. answer "Continue Anyway" to "Hardware Installation" warning

Done!