In the Plug-In Manager click on <Add> at bottom left, navigate where your plug-ins are stored and select them.
On Windows, in Lr 3 the plug-ins were in this folder: Users\[your usere name] \ AppData \ Roaming \ Adobe\ Lightroom \ Modules.
In the Plug-In Manager click on <Add> at bottom left, navigate where your plug-ins are stored and select them.
On Windows, in Lr 3 the plug-ins were in this folder: Users\[your usere name] \ AppData \ Roaming \ Adobe\ Lightroom \ Modules.