Installing of python scrips not working

Hi folks, My very first post here.

I just downloaded the 2.6 bool tool script…but it doesn´t seem to be recognized when I installed it.
Usually I install it on secondary harddrive :E and a folder called blender addons, have done that before and it worked for some scripts.
I tried that…but the plugin doesn´t even show up in the addon list, been looking for it but is nowhere to be found, I installed it from file, then I tried to install it from this path
:\Users\MI 1\AppData\Roaming\Blender Foundation\Blender\2.76\scripts\addons

but I get an error “sourcefile is in the addon search path”

tried installing from where most others plugins are but get the same error.

What addon are you trying to install ? A search brings up more than one called bool tool
Link ?
Is it a zip file or .py file etc
Are you following the installation instructions

To answer my own problems …
It worked in a later 2.77 versions, not int 2.76b though.