So, my situation is, I have a PC with two network cards, one is a physical ethernet adapter, the other a wireless adapter. Both network cards are on the same subnet. I need to be able to forward IP packets from one adapter to the other.

I have already attempted to use a bridge and this does allow the packet forwarding to function. The problem with the bridge is that it changes the MAC address of packets that go through it. There are devices on the network that cannot handle this.

I have also just tried setting the IPEnableRouter registry parameter, since apparently that does what I need. However it seems to have no effect. 

I suspect the issue here may be that they are both on the same subnet, so the routing logic in windows just sends it back out on the same adapter.

Anyway to connect these two NICs?

Cheers