Modem on-line, router not

I have a similar, but slightly different problem from the other posts thus far. I have two laptop computers I'm trying to run on one wireless router. One Dell is running Vista, and the other XP. The wireless router is a Netgear WNR 2000 router. Everything worked fine last night both plugged in through an ethernet cable and wirelessly. This morning, when I powered everything up, the router no longer wanted to pass the internet signal to the computers. Both computers can still connect to the internet while plugged directly into the modem, but when I try to run the signal through the router (wired or otherwise), I only have a local connection with no connectivity. Does anyone know what I'm doing wrong?