dfu programmer for Windows
You can use dfu-programmer to program you device(Atmel AVR controller) on Windows.
Download dfu-programmer-x64-1.x.x.zip and unzip all files in a folder.
You will have to install WinUSB Driver for your device before using the tool.
Follow these instructions.
First, You need to start Flash mode to program your device. Just press button on the device.
Then, run three commands to flash new firmware on your device.
The first command removes existing firmware on controller you have to erase it before programming controller.
The second one programs new firmware actually, your_firmware.hex is filename or filepath of your firmware.
The third one restarts your device and starts new firmware. This command is optionaly, you just can re-plung instead.
dfu-programmer.exe atmega32u2 erase --force dfu-programmer.exe atmega32u2 flash your_firmware.hex dfu-programmer.exe atmega32u2 launch
In this example atmega32u2 part may be atmega32u4 or other depending on your device.
Open unzipped dfu-programmer folder in File Explorer and select 'Open command prompt'(or 'Open Windows PowerShell') from 'File' menu.
Click to see image at full resolution.
Note that your folder path is showed in comand prompt. And type and run above commands line by line. Optionally you can drag and drop your firmware file from File Explorer to Command prompt window instead of typing long file path.