When you open Hindenburg it will automatically scan your computer for existing plugins.
1) The path specified by VSTPluginPath in the registry
2) C:\Program Files (x86)\Steinberg\VSTPlugins
3) C:\Program Files (x86)\VSTPlugins
When a folder is found with plugins, then Hindenburg will assume that all plugins are in that folder.
So, It's a good idea to use the same folder for all Plugins.
When you add a new plugin Hindenburg will detect it and add it to your list of plugins.
To force a rescan of all VST plugins delete the file above and restart Hindenburg.
If you want to try a third party plugin that is guaranteed to work, try this one:http://loudmax.blogspot.com