Installer won't let me install the demo version of Traktor Pro 4 while Traktor 3 (fully licensed) is still running. Does this mean that the new demo will overwrite my existing installation, or can we safely run both at the same time?
Then close Traktor 3 during the installation.
There will probably be conflicts with drivers that are currently loaded while you are installing the new program.
Traktor 4 will not overwrite Traktor 3.