Custom ATMEGA2560 (w/ ATMEGA16U2) Programs But Not Recognized by Windows Device Manager

[arskiracer]

Here are the last two links to the things I've tried so far that couldn't be posted above due to new user limitation:

How do I update the bootloader of Atmega16u2?

My current bootloader is 1.0.0. I think this may be causing some issues. What file should I use to update the bootloader using Flip? Where can I find the file? Thanks! [Bootloader.png]

Updating the Atmega8U2 and 16U2 on an Uno or Mega2560 Using DFU | Arduino...