Two notebooks aren't finding Wifi after outage

All: My netgear router got turned off accidentally... and when I turned the router back on, I had lost my two macbook connections (a new macbook air and a really old macbook). I know the wifi is working as my ipad grabs it, but it won't work on the two notebooks despite my trying to connect to them. I have turned the wifi on in each of them. Any tips on what I should try next?

Can you see the signal? If so, try "forgetting" the network in System Preferences before reconnecting.

Was the router set to assign specific IP addresses to devices, or to limit the number of device IP addresses that are allowed on?