If you want to save swf files from the webpage the simplest solution might be just to select File->Save page as… and choose desktop. If the webpage you’re trying to save has pictures, flash files and other material all of these will be saves in a separate folder next to that page’s html file. So after save operation open this folder and look for the wanted swf file inside.
If you find many swf files and don’t know which is which, then I would suggest installing Firefox extension called Firebug.
Install it and run inspection tool on the site you’re interested, locate sfw file name in the html code and search for this file in the saved folder location on your desktop.
This simple solution helped me to save swf file that I needed very quickly and without additional plugins which can slow down your computer.