Question about UNO R3 Mega16U2 firmware programming

Hello, Dear,
I have several questions about the firmware program to Mega16U2:

  1. How to get into DFU mode?
  2. Which program tools to use for the programming?
  3. How to setting the fuse?

If there is detail program step introduction, more appreciated, thanks!
Now I want to use flip to program, but it show that "AtLibUsbDfu.dll not found","Could not load dynamic library".
When I load the hex file "Arduino-usbserial-atmega16u2-Uno-Rev3.hex" to the flip, it shows "Address is out of range"

Hello,
I have exactly the same questions. My Mega 16U2 is not recognized anymore wuthin Windows XP and trying to flash it vua DFU mode but with no success.
Anyone able to help? Seen many references for DFU mode in other boards but not with this one. How to enter into DFU mode? How to know the board is on DF
DFU mode?
Help is pretty much appreciated.
Rgds,
Jaime.

Have you tried searching this forum for DFU ? Search box is top/right of the page
I get 11 pages of hits when I do the search so it is a subject that has been discussed here.