Check your modem and make sure all the plug connections are snug. The modem should be powered on. Check your Ethernet cable to see if it is plugged into the correct port on your Apple AirPort router. The Ethernet cable from your modem should be plugged into the WAN port on your router, which is marked with a circular icon composed of small dots. The AirPort should be plugged into your wall outlet. If your airport blinking yellow light continuously, then try resetting your modem. Examine your model for a tiny reset button or unplug it from power for a couple of seconds. The modem might take a few minutes to reconnect to your Internet service.

Read more: windows airport utility