EZD and EZD2 won’t run side by side on the same system. Ezdrummer2 will replace it and automatically load in place of the EZdrummer 1 instances in your existing projects. All the settings you made to EZdrummer in those projects will be preserved and playback will be exactly as it was, but you will gain access to the features and controls available in EZdrummer 2. I’m totally serious 😉
