In network situations, when every PC is not working, the problem typically isn't a matter of incorrect settings and the next step would be to power cycle the wireless CPE. If it is a single PC connected directly to the wireless equipment, try restarting the PC first and see if the connection comes back.
One cable goes to your PC or router, another goes to the antenna, and the last cable is for power. If the Internet is down for all computers that should be online, unplug the power from the device and wait ten seconds. Plug it back in, give it 30 seconds, and see if the connection is restored. There should be lights letting you know that the device is receiving power.
If your connection doesn't come up after that, try power cycling your router like you did with the CPE (If you do not have a router, simply restart your computer). If you are not sure what device is the router, it's a box that networks your computers together
