If you get the unable to establish connection error in CS2 then the first thing you have to do is to ensure there's nothing wrong with your internet. If that isn't the cause, then restart CS2, verify game files, and disable any background applications you might have enabled.

If CS2 won't launch, the problem might be hiding in your game's files, particularly a damaged or missing exe file. Damaged or lost game files can cause various launch issues. There's a straightforward solution: – check the integrity of your missing game files within the program files folder.