Turn off all computers on your home network, then turn OFF the router, (unplug it or use the on/off switch), then turn OFF the modem, (if it's separate from the router), then wait five minutes. Now turn ON the modem, wait two minutes for it to reinitialize, then turn ON the router, (if it's separate from the modem), wait two more minutes, then turn ON your computer.

Hope this helps.

Grif