Cannot install Add-On (Animation Nodes)

I wanted to install the Animation Nodes Add-On, went to the official download link (, downloaded the zip file, went to Blender (2.79) User Preferences, Install from File and everything seemed okay, but I could not find the Add-On afterwards.

So I went to a subpage on Github (, downloaded the windows-version zip file, installed it and it shows up in the Add-Ons list. Unfortunately, when I want to activate it, I get an error message “There are multiple versions installed…remove older versions”.

How can I uninstall a version that does not show up?

Soo many thanks to you gurus upfront!

P.S.: These are my machine specs: Intel i5-4200 CPU @ 1.6GHz 2.3GHz, 8Gb RAM, Windows 8.1, x64.

AddonsDirectory = C:\Users\UserName\AppData\Roaming\Blender Foundation\Blender\2.79\scripts\addons
Delete old Animation nodes file.

Thanks so much özgür!