1) Create a folder somewhere other than in your PSP program files for filters.  That's because PSP will load real slow if too many of these things are installed in it's program files.  I have my psp extras folder in my C drive, but it can be in your Documents folder or wherever.  I have each extra in it's own sub folder.  For example, I have the main PSP Extras folder in my C drive.  Then in that are sub folders...Plugins, Tubes, Masks.  In each of those are more sub folders.  For example, the Plugins folder has sub folders named for all of the plugins I have.  "Factory Filter Gallery A", "Xenofex", etc.  Before I download a plugin, I create a new folder named after the plugin in the plugin folder.  Then I download that plugin to it's own sub folder and unzip and install to that same folder.  It's important to keep them all in their own sub folder because otherwise it will be a mess because one plugin contains several files. 

2) You have to make PSP recognize the folder.  Do so by doing this...
3) In PSP, click on "File / Preferences / File Locations".
4) Click on the "Plug-in filters" tab.
5) Folder #1 is probably already filled in because it's the default folder.  So fill in Folder # 2 by clicking on the Browse button.
6) Find the path to where you created your new filter folder.
7) Highlight it and then click OK at the box.
8) Have the first 2 things here checked..."Enable filters...". and "Include sub folders when searching for filters".
9) Now OK the remaining box and all filters you put in the filter folder and it's sub folders should now work with PSP. 

You may have to restart PSP for the filters to take effect.
Open a graphic in PSP and find the filter effects by clicking on "Effects / Plug-in Filters".

~Summer °Ü°