You are facing a no win situation from the condition that you describe.
You cannot open project files from Premiere Elements Windows in Premiere Elements Mac. And, you cannot open project files from Premiere Elements Mac in Premiere Elements Windows. That is the case if you were dealing with even Premiere Elements 13 to Premiere Elements 13 in contrast to Premiere Elements old to Premiere Elements 13.
Even if you are going from Premiere Elements old Windows to Premiere Elements 13 Windows, there is no guarantee that the old project file will open in a later version. The classical recommendation is to finish a project in the version in which it was created. And, project file from early version opened and edited in later version cannot be taken back to the earlier version for editing. In that case, you work from a copy of from the older version, "just in case".
Please review and consider, and then let us know if you have questions or need clarification on the above.
that is totally depressing
I was hopeful but darn!!!!!
Thanks for the reply. Sorry the outcome could not have been better.
If you had Premiere Elements old on Windows still available, you could always export the Timeline to a .mov or .mp4 file that you could import into a Premiere Elements 13/13.1 Mac project and cut it if necessary. But, the whole issue starts with your Windows computer no longer being available.
If you can find another Windows computer on which you can install Premiere Elements to finish off those projects, do not forget to transfer the project file along with it source files. Did you by any chance save those projects as archived projects using the program's Project Archiver with its Copy Project option? And, if Movie Menus are involved, make sure that the Movie Menus theme in the project has gone through the content download process in Windows computer 2 so that it is available for use in the Windows computer 2 side of things.