So, I was trying out Windows Server 2012. I tried installing freelan (http://www.freelan.org) as a service. If you know me, I'm a big fan of freelan, but for some reason, after every cold boot, there was no connectivity to the node over VPN. Specifically, this problem was only occurring on Windows Server 2012.
Generally speaking, I think it has to do with the freelan acquiring the OpenVPN TAP adapter. Changes in the operating system driver infrastructure in Windows Server 2012 somehow goofs up the freelan application as it tries to initialize itself and the driver.
Turns out, you need to force the TAP adapter to a connection state of "Always Connected". Somehow, when the TAP adapter is set to "Always Connected", Windows then makes the TAP adapter available to the OS networking infrastructure. So when freelan tries to initialize it, it's available for use. Network problem solved.
Here's how to do it. First, open the TAP adapter status, then click Properties.
Next, click Configure.
Set the Media Status to Always Connected.
This probably has a lot to do with people generally using OpenVPN's TAP adapter on Windows 8 or 8.1 too. Or, maybe freelan is just packaged with an old out-dated OpenVPN TAP adapter.