If you have transferred a project to a mac to another if logical the files paths aren't the same you'll need to relocate the files...
Not a big deal if you saved properly on the other computer.
If you are talking about the full S1 software, and that you have copy/pasted all the files of it to another mac thinking it will install it like the other you were wrong and need to delete everything before making a clean reinstall with the proper installer from your Presonus account.
Not sure by what you mean with "I don't want to keep having to come back here when I restart my computer & my files are gone " . Normally if your computer is fine and except if you have partitions rules to reset some disk partitions on each restart, you should loose any files when restarting your computer....
Hope this may help,