Troubleshooting Ruby, Netbeans, sqljdbc

Hello everyone,
I posting this after doing a good deal of unsuccessful researches.

I am running windows with ruby 2.3.2 and working with netbeans. I just
switch my project from running on the built-in ruby of nb, and now the
application give me this weird error:
establish_connection': Please install the jdbc adapter:gem install
activerecord-jdbc-adapter` (no such file to load – java) (RuntimeError)

I have installed activerecord-jdbc-adapter 0.9.1 and I get the same
error. I downloaded the sqljdbc.jar but I don’t know where to place it!
I read somewhere that it needs to be in the lib folder. Can anyone who
knows be more specific? last time I checked there were about 16 lib
folder within the ruby folder!

I have the same problem on a Mac running Leopard, so I believe it has to
do with the jar file, but don´t take my word for it. If you have any
idea please let me know! My brain hurts !

Thank you