I use Ardour5 (64 bits) with Windows10 just a couple of days. I need a noise gate. I found the free Floorfish (http://www.digitalfishphones.com/main.php?item=2&subItem=5).
Whatever I try, I can’t get it working. Can somebody help me? In which directory do I have to put the dll? Or will it not work this way at all?
You put the plugin wherever you want (there is no standard location for this on WIndows). Then you make sure via Ardour’s preferences dialog that the VST search path includes the place you put it.
That plugin is only available in 32-bit, which is not compatible with 64-bit Ardour. You will need to use the 32-bit version of Ardour or find a noise gate plugin that is available in 64-bit.