So I switched my VPN application from OpenVPN to another one on Windows 8 x64 and it broke my TAP driver installation. Following is definite solution on how to install TAP driver on windows 7 and windows 8 x64 for OpenVPN and any other VPN applications that rely on this driver.
I tried a lot of reboots, registry deletions and several reinstall of my OpenVPN and custom VPN application but it didnt seem to work. The issue of failed TAP driver installation arises when you are trying a driver that isn’t digitally signed by Microsoft. I found a great workaround for this – Instead of disabling digital signature checking on your Windows and taking risks, Just install the VPN client from PrivateInternetAccess [ linked below ] (they offer this for their paid customers, you dont have to use the app or pay them , just let their client installed the signed TAP driver – then uninstall their pia_manager client).
You can then keep using the TAP driver from their installation with any Open source VPN client.
1- To get the digitally signed TAP driver for windows 7 and Windows 8 x64, click here and get the Windows-compatible setup from PrivateInternetAccess’ site .
2- Run the setup . This will install the digitally signed TAP driver 32 v9 as well as their proprietry vpn clien.
3- Uninstall their pia_manager client. (make sure you dont manually uninstall the tap driver after this)
4- You can now install OpenVPN or any other app that uses the TAP driver. Tada! you are done.