akeemdadream, welcome to the forums.
One reason it isn't working is that according to the download page for your laptop,
Gateway Support Drivers & Downloads
based on the audio driver frm there it has the Conexant audio chip in it, not Realtek. I would start with uninstalling the Realtek driver and any software that may have been installed with it, then use the Vista Conexant driver from gateway,
Windows Vista Audio Driver version: Conexant 6.14.10.0575
which should install without much difficulty (no promises, but it should install).