To redirect all traffic from VPN clients through the VPN server, you have to configure NAT.

At this step I assume that you have OpenVPN configured properly, if not please refer to the manual [http://community.openvpn.net/openvpn/wiki/Easy_Windows_Guide].

'''1. Enabling IP forwarding'''
Press Windows+R and type: 
{{{
regedit.exe
}}}
Now navigate to the: 
{{{
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters
}}}
and set 
{{{
IpEnableRouter
}}}
 to 1

'''2. Installing role'''
Open {{{ServerManager}}} and click on Install role[[BR]]

[[Image(http://www.windowsnetworking.com/img/upl/image0081260538266451.jpg)]]

[[BR]]
Click Next [[BR]]
[[Image(http://www.windowsnetworking.com/img/upl/image0101260538400669.jpg)]]
[[BR]]

Wait till Windows complete instaling new role.

'''3. Configuring NAT'''
Open Routing and Remote access console from Administrative Tools, right click on your server local name and select 
{{{
Configure and Enable Routing and remote Access
}}}
In a wizard click on Network address translation(NAT)[[BR]]
[[Image(http://www.windowsnetworking.com/img/upl/image0121260538400669.jpg)]]
[[BR]]
In next step select your network card that have access to internet and click Next.[[BR]]

Last thing to do is to select VPN Tap-win32 network card and finish wizard.

NAT should be working from now.