Configuring two networks on a Windows 7 machine may result in a “no network access” error message. First, I assume you have checked to make sure that the NIC driver for the second network card is not having problems in device manager via control panel.
If your first NIC card is set to DHCP to connect to your ISP, then your second NIC card is set to static ip address to connect to your internal network. You can try disconnecting your first NIC from your ISP, and trying to setup your second NIC with a static ip address that is on the same subnet as your internal network, for testing purposes. You should be able to at least ping your internal network device(s) by putting the second NIC on the same subnet as the internal network is setup on.
For example:
LAN NIC card
IP: 192.168.1.1
Subnet Mask: 255.255.255.0
Gateway: blank or 192.168.1.2 (same as your DNS)
Preferred DNS: 192.168.1.2
Your internal network device could have the ip address of 192.168.1.2 on the 255.255.255.0 subnet mask. This is all dependent on if you are using a hub, switch, or router to connect your second NIC to your external network device(s).
Don’t forget to try adding your Windows computer to the same work group or domain that your domain server is on. Here is a quick tutorial showing you how to add it to the same work group.
The following networking tutorial is for Windows Vista, but I think this may be your answer for two networks on Windows 7.
