The two primary functions of GoToWebinar are to share the Presenter's screen and conference call audio. This is why outdated video and audio drivers are often the most common cuase of software crashes when hosting or attending a GoToWebinar.
There are a couple of ways to check for updated drivers, I found a YouTube video that you might find useful: https://www.youtube.com/watch?v=34eeYJVtWg4
If it finds an updated driver it will download and install it for you. Often Windows will say the best driver is already installed, in which case you may want to check the manufacturer's website directly (this is why we made a note of the type of video card you have).
You may come across two posts I made about poor video (I beleive the real problem is the unavailability to upload PowerPoint (with imbedded video)). Just as an FYI to you I did check to confirm my video driver is up to date. If you have time, recommend you take a look at my video posts to get my whole story.
Yes, your issue is different and would not be resolved by simply updating your video drivers. I will respond to you about your issue on those other posts.