How do I reset my 2007 chevy cobalt anti theft system?

I have a 2000 Chevy Cobalt 2.2 L and one morning after coming back from getting coffee I realized I forgot something and came back to the car to run to the store and turn the key to see nothing but the anti-theft system light on and the battery light. I went through all the key reprogramming steps which I went through the whole entire step process twice essentially just draining my battery. In my case when I would turn the key I would get absolutely nothing but one click and like I said just the battery light and the anti-theft light would come on and also to be clear the light stayed solid it wasn't blinking. After research I decided to unhook the battery in the trunk then went under the hood and unscrewed the lead battery post which runs directly into the fuse panel. I proceeded to clean up the connections on both sides of the eyelets of the positive and the negative also cleaning the bottom of the post. Put all that back together tighten everything up hook the battery up and honestly didn't expect too much but it fired right up. Not sure why the Anti-Theft light came on in my instance but the corrosion I had on my connections were somewhat considerable so it may have been just that or disconnecting my battery for a period of time may have reset my ECU. Hope this helps anybody with similar issues as I hear this is common with this vehicle.

Anti theft light on not getting fire won't start wat should I do please respond

I got a 2007 cobalt and its ran fine I got out and shiut it off got in little later turned it over it will ty to start but dont seem to get fire, idk soundsalitle weak wen cranking.it o er,wat could be the problem , firstsign wen wouldn't start

To reset the anti theft system in a 2007 chevy cobalt unlock the door with the fob, open the door, press the door lock button on the door card, then close the doors.