The computer install TMG can't access network

Hello Everyone

My computer has installed Winserver 2008 R2. It have 2 card network. 

Lan network Card : 192.168.1.254/24

Internet network Card: get IP automatic

My computer can access network

But when I installed TMG. My Inetrnet Card can't get IP automatic and I can't access network

I created access rule : Protocal :Allow outbound traffic, From: Internal, To: External

but It is not success

Help me