1. Open any web browser installed on your computer.
  2. In the address bar write 192.168.100.1
  3. After that click on go or press enter.
  4. You will see the Arris modem default webpage
  5. You will see Arris, status is in a yellow box. On the right side you will see wireless tab, click on it.
  6. You will see new window asking for  a username and password:

Username: admin
Password: password

  1. Then click apply
  2. Here you see preshared key after scrolling down to security settings, here you change this to any password you want to set it.
  3. Always write down the password so you never forget it.
  4. At the end just reboot the modem by shutting down your computer completely, then power off your modem. 
  5. After 2 minutes power on your modem, you will see 4 solid lights.
  6. Now power on your computer.