mix-up with my router

Hello!

Earlier this week our cable tv and computer were inadvertently disconnected at the cable station. The problem was on their end, they said, and they worked with my son and my wife to get us back online. But our laptop will not go online.
The signal is great, but we've not hooked something up right, or the router is going bad. My feeling is that we have not hooked something up right, because the router is only around a year old.
Right now I just have the modem hooked up to the computer for this main computer to be up and online. Can you point me in the right direction?

Thanks!