hmmm this sounds more and more like a windows issue, not an OpenVPN issue. Or rather, an interaction issue between windows and the tap-win32 adapter.
Try adding a route to the VPN client, e.g.
route add <vpn-server-lan-ip> mask 255.255.255.0 10.8.0.5
so that you can reach the LAN address of the server itself. Then try
start \\<lan-ip>
to see if you can reach the LAN address.