Its Not Working!!!?

We have a renault megane with three problems.
1) Sometimes the car just refuses to start there is nothing happening, we cant work out why, other times it starts up first time constantly.
2) The passenger door window doesnt work, why is this and how can i get it fixed without costing a fortune?
3) We cannot move the door mirrors, would i need to replace a fuse or something and where would it be?