Unable to upload to UNO

Hey, several weeks ago I was trying to upload some new code to my Uno and all of a sudden it stopped working and I haven't been able to figure out why or fix it.

The issue is that I plug the board into the computer and it's not getting a com port. I know it should be working because it is powered and I have a second identical board that can be uploaded to. I've tried different computers, OS, drivers and cords and nothing seems to work :frowning: . I've even burned the boot loader and that didn't fix it. I would love help and suggestions even if they are "ya done messed up"

Your operating system.
Windows 10
What kind of board you have. If it's a Mini, LilyPad or other board that requires extra wiring, include a photo of your circuit, if possible.
Uno, nothing is connected
Whether or not you were ever able to upload to the board. If so, what were you doing with the board before / when it stopped working, and what software have you recently added or removed from your computer?
Yes I was able to upload before, I was trying to upload code, no software was changed between
when it started and it stopped
The messages displayed when you try to upload with verbose output enabled. To do this, hold down the shift key while clicking on the upload button in the toolbar.

avrdude: Version 6.0.1, compiled on Apr 15 2015 at 19:59:58
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2009 Joerg Wunsch

         System wide configuration file is "D:\Arduino\hardware\tools\avr/etc/avrdude.conf"

         Using Port                    : COM3
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
avrdude: ser_open(): can't open device "\\.\COM3": The system cannot find the file specified.



avrdude done.  Thank you.

Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
Board at COM3 is not available

Thanks!

It can't open port. Port can be locked by other application, missing driver or some problem with port circuit on UNO board. Isn't it dimmed in IDE - menu port select? Which UNO, genuine or clone or better, which type of chip is on USB/serial (ATmega16U2, CH340, FT232RL...)? Check the device manager in Wins if the device and port exists there.

The board is not showing up in in device manager, the USB/serial chip is ATmega16u2 and the board isn't a clone or genuino. My best guess is that the USB/serial chip got screwed up, but if you have any ideas I'm all for it :confused:
Thanks

Use your working Uno as an "Arduino as ISP" and burn the Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex file onto the ATmega16U2 using the ICSP header near the USB port. You should be able to use the avrdude command line to do this. That will probably fix it.

If you don't know how to do that, write back for guidance. If you go into the IDE preferences and check show verbose output for uploads, then show us the complete text the IDE shows to you when you upload to the good Arduino, that will help.