Q:

Can't deny user access to a library when he is inside the "All Users" group

I'm trying to give an user access to just one folder in our main library, first I gave him permission to access the Site and then I went on the folder that I would like him to have access to and stopped inheriting the permissions, then I added him as an Editor.
The problem that I'm having is that when I give him permission to access the Site he's added in to a group called "All Users" and this group is granted access by default to the entire library, what I expected was to see him listed outside of the group where I could edit the Library permissions and remove him.
I would appreciate any help on this.
Thanks
I'm on SharePoint foundation 2013.

A:

i dont know if you have done this: but cant you give access to the list only? you dont need to give him/her access to the site... 
You need to goto the list settings and remove inheritance. Now go to permissions for this list and add the user there! Remove any instance of the user from the site groups and users. 
when the user access the list directly(url to list) obviously he would have access depending on what view you gave him to have access to.
If he were to try and goto any other page it would show an access denied page! 

