Good day,

1. How can I re-use my edited pcf files?
Everytime I run generate isometrics, my edited pcf is overwritten by the default pcf.

2. How can I change the default pcf editor to a different application instead of notepad?

Thank you.

1) I think it's supposed to create new pcf file every time you generate isometrics. If you want to reuse it, save the pcf elsewhere (or different file name). Next time you want to reuse it, you can click generate isometrics, edit it, and overwrite it with the content of the other pcf file.
Or you can just copy and paste the content of the pcf you want to preserve in a different window of notepad.

2) I'm guessing that you can change file association in windows to the program that you want. In Windows 7, press the Windows Start button, type "Make a file type always open in a specific program", run the application with the same title that pops up. Scroll down until you find .pcf. From there you can change the default application for the file type.