Uno R3 as USB HID device/ Firmware update

Good Evening all

I would like to force the device to be recognized as a usb-hid keyboard, 
and not an Arduino. I have tryed to put the device in firmware update 
mode and use Flip to upload an update to ATmega16u2, but when trying to 
short the pins I am not ending up in firmware update mode.

How to Make a Arduino HID Keyboard : 18 Steps - Instructables is the 
tutorial I was working through. And before someone asks, I have a 
Leonardo board that works in some instance in the target application, 
but this solution is a must for interfacing with a Windows 97 embedded 
that is in accessible. So the pop up for the unknown device blocks the 
keyboard functionality.
So as a secondary question is there a simpler way to achieve this then 
using flip and no boot loader?

I look forward to responses and insight
Thanks
Matt