1995 Pontiac Transport Power Windows?

I have a 1995 Pontiac Transport that just yesterday both of the power windows stopped working. I put the windows down after starting it up to go to work, about 20 minutes later I tried to put the windows up and they no longer work. That night I got a new 30 amp circuit breaker and replaced the old one, still the windows don't operate. Other than the circuit breaker what can cause both of the windows not to work?