Hi regrossman,
1. Open file D:\2005\Gallery\CuteSoft_Client\Gallery\Viewer\LightBox\Code.js
2. Find section below, the red code is the width and height you want to change
this.img=GalleryCreateImage(photo.Url,imgwidth,imgheight);
this.img=GalleryCreateImage(photo.Url,300,200);
Regards,
ken