Windows or any program will not use more ram than it requires, if ram is low the program might have low framerate issues or freezing. But if there are more ram than needed, There won't be any problem when working a program or a game on that computer.
If you would like to remove excessive ram, you can take one of the ram card out. or limit the ram usage by certain settings.
For extensive support please ask the person you've bought the card from or ask / call a person that you believe is knowlegable about this subject.