Regardless of what caused it, your main goal will be to reconnect your HP printer to the network and get everything back online. It would be best if you began by rebooting your router. To do this, disconnect the wireless router's power cable and wait at least 10 seconds before connecting it back in. On the router, you should see a light turn on. The next step is to turn off and then on the wifi functionality on your HP printer by pressing the wireless button. Unless there are any other issues, all you have to do is wait for your HP printer to reconnect to your router successfully. However, if by following the above line still your issue of HP Printer not connecting to wifi is not solved, follow the other steps.