OpenVPN failed connection / All TAP-Win32 adapters on this system are currently in use [closed]
I found a solution to this. It's bloody witchcraft, but it works.
When you install the client, open Control Panel > Network Connections.
You'll see a disabled network connection that was added by the TAP installer (Local Area Connection 3 or some such).
Right Click it, click Enable.
The device will not reset itself to enabled, but that's ok; try connecting w/ the client again. It'll work.
It seems to me you are using the wrong version...
TAP-Win32 should not be installed on the 64bit version. Download the right one and try again!