How can I render a video if one of the parts of the video is 1 GB?

So lets say I have 4 parts of a video, 4 different cuts lets say. And one of them is 1.54 GB (the file size) and when I try to render it, it doesnt want to render. Overnight it only got to 9.5% and didnt move any further. Im using Camtasia 9.PLEASE HELP