20 Aug. 2012
Starting with Windows XP you can open zip files by double clicking on them. What you find inside is a copy of your PAF database, which is a specially formatted file and essentially unreadable except in PAF itself (there are text lines in the file that are readable).
The advantage of the backup file is that it can be read directly into PAF without going through the import and conversion step necessary for a gedcom.
Unless you are sending the gedcom to someone else to import into their genealogy program (the reason that the gedcom format was developed) or are using it as the input for some other program, there's no need to export your PAF into a gedcom, except perhaps as a safety precaution.
If you are comfortable using the command line, you can go to the folder where your PAF files are stored and use the command:
to delete all the backup files (they will not be put into the Recycle Bin, just deleted). But PAF will continue to prompt you to backup your file.