In Hyber-v of win server 2012 how to connect virtual win server 2012 to the physical Network via virtual switch

To begin, launch the Hyper-V Manager using the tile on the Start Screen, navigate to the Actions pane, and select the Virtual Switch Manager action.

When you see the Virtual Switch Manager screen, you'll notice that the first thing that you must do is choose what type of virtual switch you want to create. As you can see here are three options: External, Internal, and Private.

• When you select an External virtual switch, your virtual machine will be able to access all resources available on your physical network including host machine and the Internet.
• When you select an Internal virtual switch, your virtual machine will only have a network connection with the host machine. In other words, the virtual machine will not be able to access resources on your physical network nor will it have access to the Internet.
• The only time that you would want to select the Private virtual switch, is if have more than one virtual machine running at one time and you only want a connection between your virtual machines.

In your case you have to chose the External Virtual Switch.

When the Connection type is set to External network, you'll see that your system's network card is shown in the drop down text box and that the Allow management operating system to share this network adapter check box is selected

it works fin now Thanks very much