If you receive your Internet via a wireless router in your home, the router more than likely connects to a DSL modem. The DSL modem brings in the Internet from the outside and the wireless router converters it to a wireless signal. However, your current wireless router may not cover your entire house, in which case you may want to add a second wireless router to the DSL modem.
Insert an Ethernet cable into the first out port on the DSL modem. Attach the other side of the Ethernet cable to the "Internet" port on the wireless router. Connect the router to a power source if it isn't currently connected to one.
Insert an Ethernet cable into an out port on the wireless modem and insert it into the Ethernet port on a computer. Although the wireless modem is made to be wireless, you do need to activate it through a wired connection.
Launch the Internet browser on the computer connected to the wireless router. Look on the wireless router and you are going to find an "Http:" address listed on the bottom (typically looks like "http://192.....). Type this number into the search bar and press Enter.
Follow the prompts on the screen and the wireless router is activated. You can remove the Ethernet cable running from the computer to the router.
Connect a second Ethernet cable to the second free port on the DSL modem. Insert the other end of the cable into the "Internet" port of the second wireless router. Follow the same steps of activating the second wireless router.