Woah hold on. There seem to be some extreme solutions here or I am not understanding your problem.

The way I remember it you can play Chapt 2 til the end but you dont automaticly move to Chapt 3. I had to go back out to the main menu and select to start Chapt 3.

Just so you know...you pretty much start over again. Its kind of like moving to the next lvl in Command & Conquer. So those badass Generals that you have in Chapt 2. right now; say goodbye to them =(