Arduino Uno and Mega Communication Issues

Hello.

I was noticing quite a few communication issues with users of the Uno and the Windows IDE. When reviewing screenshots of the Device Manger, I noticed that COM3 was being assigned to the quite a few Uno boards that were not uploading sketches, yet when in the IDE, COM3 does not show.

It would be nice to get an idea of how widespread this issue is. If you would post in this thread just the information in addition of posting you topic in the main Installation & Troubleshooting, it would be greatly appreciated. This thread will mostly be collecting information.

Information Needed:

1. Platform (Uno, Mega256, Leonardo, etc)
2. Error Message (e.g. avrdude: stk500_getsync(): not in sync: resp=0x00)
3. Has the Installation Worked Before? (Yes/No)
4. When Connecting to USB, Computer Makes Connection Tone? (Yes/No)
5. Communications Port Assigned (COM1, /dev/ttyACM0, etc)

Thanks in advance!