How do I install this script or is the function in blender or another script? Thanks

I found an add vertex script but I get the error: Source File is in the addon search path ‘C:\…scripts\addons’

There is a list of add-ons that can be activated in Files>>User Preferences>>Add On tab

Generally I know how to install scripts. I’m wondering why I get this error? The script has a check mark in the addons panel , but I cannot find the function even when I do a search. Where and would I find the function in the left panel?

In the list Orinoco mention is a button “Install from File”, use this to install .py or .zip addon files.
If is not a addon file but a python script open it in Blender text editor and run it with Alt+p

Cheer, mib.

EDIT: Sorry, to late.
Please add a link to the script, may it don´t work in newest Blender versions.