Hi ag858 -
Can you post a screenshot of the offending node and set up you are using in 4.7.6 and in 4.9.1? I know that there was an issue with the Post Processing Node causing a Video Driver crash, but this was a new issue specific to 4.9. If you could also take a look at the Windows Event Viewer and post the logs that windows generated when the engine crashed for you.
You can use this wiki for reference to using Windows Event Viewer:
Thank You
Eric Ketchum