Over its lifetime, every piece of hardware needs updates. Routers also require firmware updates to function with various operating systems or hardware configurations. Unfortunately, outdated router firmware can cause problems, such as the Netgear router WIFI not working. Verify that it is not your ISP's fault and that you are receiving a reliable internet connection. You could check with the ISP or use a different spare router to confirm. Additionally, you can test your internet connection by directly connected connecting an ethernet cable to your computer. Finally, for the internet to function, you might need to enter your computer's internet settings.