I was able to force my external monitors to run on the NVidia card and the laptop to run on the Intel. Unfortunately, I forgot how I did it.
I ran so many troubleshooting steps trying to fix this that I cannot say for sure. You might try installing new USB drivers from the manufacturer's website. I had to follow these steps to update my USB drivers as Intel does not write any for Windows 8:
http://plugable.com/2012/12/01/windo...st-controllers
I also disabled the following Intel services - hkcmd Module, igfxTray Module, and persistence Module. They were set to auto start but are now set to disabled.
You can download DevManView from nirsoft.net and write a batch file to run at startup to automatically enable the Intel graphics card. At least then if you forget to re-enable it before shutdown, you will be able to use your laptop when you are away from your external monitors.