If your goal is simply to open an old .P3 or .PMX file from a past project, you do not need to install P3 v3.1.
: Relies heavily on DOS-type shortcut keys, which provided high efficiency for experienced users before the shift to mouse-based interfaces. Modern Alternatives & Migration Primavera P3 Version 3.1 Free Download
Beyond legality, here is the real-world truth: If your goal is simply to open an old