How do you fix the power windows and locks on a 97 Ford Taurus?

[Fenix]

My friend received a 97 Ford Taurus when his grandfather passed and the wiring inside is all messed up. The power windows and locks don't work except on the drivers side. He can lock/unlock all the doors and roll up/down all the windows from the drivers side control switch but none of the switches on the 3 other doors work at all. What could be the problem? And how can he fix it? Also could this prevent the car from passing inspection in the state of maine? His inspection runs out next month. Thanks