car wont start

my car doesnt start. i dont know exactly what h appened but i went into the garage today and the car still has batteries and everything but when i put the key and turn, it just clicks and the alarm is engaged. i think it is some security thing and all my radio settings have been reset, i have an aftermarket stereo. any suggestions?

If all your radio settings have been reset, it sounds like hte car lost power. It's possible the car just doesn't have enough cold cranking amps or something is shorting out or was left on and drained it. Just because you can get power to the lights/stereo etc, doesn't mean it has enough power left to crank the car. Try going to Autozone, they will charge the battery for free.

If you have a fully charged battery and hte car still wont start, check for fuel and spark, as you obviously need both. If you don't know how to check for one or the other let us know. Both are very simple.

Lastly, any chance you did anything to the car recently?