I have two network cards with different Internet speed on each one. With this tool im able to select what nic/route to use depending on the destination of my packets.
If somehow you screwed up the routing tables, a reboot would automatically fix it because the changes that you made with NetRouteView is only temporary and not persistent.
NetRouteView is a GUI alternative to the standard route utility (Route.exe) of Windows operating system. It displays the list of all routes on your current network, including the destination, mask, gateway, interface IP address, metric value, type, protocol, age (in seconds), interface name, and the MAC address.
NetRouteView also allows you to easily add new routes, as well as to remove or modify existing static routes
Download from: http://www.nirsoft.net/utils/network_route_view.html