It may simply be your router. Go with the routine customer service response of unplugging it and turning it back on in 10 seconds first. If that doesn't work, you will need to login to the 192.168.1.1 and adjust the wireless settings.
The problem more than likely is that, if it is a Linksys router, that the system configuration settings got readjusted from Manual to Wi-Fi Protected Setup, which threw all of my devices off the network. Put it back over to Manual, save the settings, and you should be able to connect.