I\'m running the latest MongoDB for Ubuntu 14.04
Did you follow the instructions in Enable Client Access Control to create the user and enable authentication?
What is the output of your log, when you try to access mongoDB with credentials?
Did you tell mongoDB somewhere to use the config file? Try to start mongoDB locally on the PC mongoDB is running with mongod --config ../etc/mongod.conf and then try to connect from your Windows PC like you did before.