Check the Battery

• If your 2007 Saturn won't start, it could be due to a drained battery. Any number of things from a dysfunctional alternator to leaving the lights on overnight can deplete a car's battery. You can test this by connecting the battery to a voltmeter. If you don't have access to a voltmeter, try jump-starting the battery with another car and a set of jumper cables.
  
  

Check the Fuel

• If the battery is working properly, ensure that the car has a sufficient amount of fuel in the tank. If the electronic gauges in the car are still working, check the fuel gauge. If the electronics aren't working, get a gas can and add a gallon to the tank, then try starting the car.
  
  

Call a Mechanic

• If the battery is working normally and there is gas in the tank, it may be time to call a mechanic. You may have to make arrangements to have the car towed into the shop or hire a mechanic willing to assess the problem on-site.