hi, you can connect two different computer via Serial Port with connecting modem with them. you will See in front panel of modem below, it has a USB (blue) and a ETHERNET (yellow) port. i am recommended you that you may use CD that is come with your modem for installation. Now you can attach second computer with Ethernet(Yellow Cable) NOT in USB.
For connecting remotely. You should use dialup networking can be used. One pc would have to run in server mode and the other in client mode. For creating a small LAN (local area network). Then I recommend you buy two NIC's and a crossover cable. It's not only a whole lot faster, it's simpler to setup.