This feature allows you to use Virtual Studio Technology (VST) DLL plugins to apply effects to the audio you are working with in VideoPad. To use this feature, select Audio Effects menu -> VST Plugins, and in the window that appears, you can browse for the directory on your computer that contains VST plugins - note that the plugins must be DLL files! Once you have specified a directory name, you should see a list of VST plugin names appear in a list in the window. Press the "Refresh" button, if you don't see your desired plugin in the list, but it is in the selected folder. Next, click the "OK" button to see the selected VST plugin effect window.