Two internet connections at once in Windows 7

Solution 1:

Windows always controls which network connection is used. If you have multiple active network connections to the same network, then Windows will use the first one listed under Network and Sharing Center->Change adapter settings. Other network connections are unused.

If you have two network adapters and you wish to force the usage of one specific adapter, then there are two cases to consider.

1. Application uses a known website

If a given application uses only one or several known websites, and if the wired and wireless networks use different ranges/segments of IP addresses, you can use the IP address of the website(s), together with the route command to add entries in the local IP routing table that will direct such requests to these addresses through a given adapter.

For example,

route add 88.99.0.0 mask 255.255.0.0 10.0.0.1

will send all the traffic for 88.99.x.x to the next hop address of 10.0.0.1, which could be the address of the router. The router will have in this case two IP addresses over the wired and wireless segments. Traffic that doesn't match a route is sent to the default route 0.0.0.0 normally associated with the first adapter in binding order.

This technique makes Windows use both network adapters indirectly, by actually placing each on a different network (e.g., 192.168.1.x and 192.168.2.x). If certain resources are only available on one or the other network or have routes leading to one or the other, then obviously Windows chooses the appropriate network connection.

This way doesn't control directly which network adapter is used on a per application/service basis. But there is a second solution.

2. Using a virtual machine

If you install a virtual machine manager like VirtualBox, you can create a guest virtual machine (VM) and connect its virtual network adapter to any of the host's physical ones.

This way, any application started in the VM will use the designated adapter, no matter its position in the host's adapter table, so you can divide network activities by choosing between host or guest as the execution media, while both host and guest can share files through network shares.

Windows 7 has XP Mode, which is actually a closely-integrated virtual machine. Although quite lame as virtual machines go, it might be possible to use it this way (or not, as I never tried).

Solution 2:

Check this tutorial out. It uses ForceBindIP to force an application to use a specific network card. The only disadvantage is that you have to run your programs with ForceBindIP each time you start them.