I just constructed the Tumbler and using the Cortex Microcontroller and my ROBOTC software, I was able to download the firmware to the robot and using the game controller it worked fine using the default software. Is it possible to view that default software for reference? Using the USB teher cable only let the cortex have the code for it to work but I couldn't find any files from the cortex or any other sites

The actual default code is something that's provided by VEX Robotics, the manufacturer, and preloaded on the Cortex. Once you download the ROBOTC Firmware, that default code is wiped out to make room for your ROBOTC code.

That said, we've created the same functionality in a ROBOTC program, which you can find by going to File > Open Sample Program > Advanced > ROBOTC VEX Cortex Default.c

Is this RobotC code just code that will compile to something equivalent to the Cortex default code?
So, is the only way to go back to factory settings on the cortex is to use the VEXnet Firmware Upgrade Utility?

Regards,
Kevin

Yes, to both questions. It is ROBOTC code that compiles to something equivalent of the Cortex default code.

The VEXnet Firmware Upgrade Utility is the best way to revert to true factory settings.