If you have an HP laptop computer and all of a sudden it won’t connect to your wireless network any number of things could be the cause of your problem, but here is something very simple for you to check that might get you back in business.
Depending on your model, you may have a backlit button near your power button that has an antenna-like graphic on it. This button turns the wireless card on and off in your computer. If this button is an amber color, press it. It will likely turn blue and then connect to your network. If it is already blue you may have and issue with your router, modem, internet service provider, or you may have a configuration problem in your computer.