You can connect a DSL modem to a router to share a Broadband Internet connection over multiple computers; however, the modem can bypass the router and connect to a singular laptop or desktop computer. Operating Systems from before late 2001 required that the computer user manually configure the computer to work with the DSL modem, but Windows XP (and later versions), all Mac OS X versions and modern Linux distributions are equipped to automatically configure with the external modem when the modem connects to the computer.
Connect one end of the phone cord to the phone input port on the DSL modem and the other to a nearby phone jack.
Plug the DSL modem's power cable into the modem and an electrical socket.
Connect one end of the Ethernet cable to the DSL modem's Ethernet port and the other to the laptop's Ethernet port.
Turn on the computer and log in to the operating system as you would during normal use.
Select what type of network to which you are connecting from the home, business and public networks list if the computer prompts you.
Open a web browser like Internet Explorer, Firefox, Chrome or Safari and load the home page to check if the computer connects to the Internet.
The home option is safe in this instance because your computer is the only computer on the network. If your laptop is unable to connect to the Internet in step 6, your Internet service provider may require you to run special set-up software on each computer you connect to its network. If this software was not provided during installation, you can contact the service provider to obtain the software. Some service providers require that you install special software on the first computer you connect to the service. If this is the case, you will be brought to a special webpage to download this software when you load the web browser for the first time. You can view other web pages after installing the software. The DSL modem is unable to share an Internet connection with multiple computers if you directly connect it to a laptop. However, you can disconnect the laptop, connect a router to the modem, and connect the laptop to the router to reconfigure the network to work with a router; you may not need to restart any of the devices to do so either.
You cannot connect to a DSL modem over Wi-Fi without a router. If the DSL modem has built-in Wi-Fi, it is a DSL Modem/Wireless Router combination device. Do not install a phone filter when connecting the modem to the phone jack: it will distort the signal and keep the modem from working correctly.