adding library to eagle cad

hi guys!

i am using free version of eagle cad and want to add adafruit library to it but am unable to do it.
i have downloaded the library to my hard drive and added its path to the blank space next to"Libraries" under drop down of "directories". the exact path i have added is "C:\Users\USER\Desktop\adafruit.lib"
then i have right clicked the adafruit.lib file and selected "use all".
after doing this the library should show green buttons but it dosent.
any idea?

thanks in advance,

This is just so completely in the wrong spot. It is not in the right part of the forum, if it even should be on this forum.

Eagle do have a support forum too.