Yes, you can have two PAF files on the monitor at the same time; it's easy to do.
With one PAF file open, adjust the window size so that it isn't maximized.Then open your 2nd PAF file (FILE Menu, select "Open," and then browse to the location where your 2nd file is located and open it.
Now you have both PAF files open.Adjust the window sizes of each file (drag the borders, etc. -- normal Windows functions). So you can have each file take up half the screen, or you can have them overlapped.
The Tool Bar at the top is common for both files; just click on the file you want to be "On Top" at any given time.
-- Cliff in Virginia William C. Barney President, Barney Family Historical Assn.