In order to flash new firmware to your, you need to be in boot loader mode. We will go over four options.
Option 1: Use The BetaFlight Configurator
BetaFlight Configurator allows you to put your quad in boot loader with mouse clicks if you have a recent firmware and the latest BetaFlight Configurator. The video below shows you the first option.
Option 2: Impulse Driver Fixer
Download the impulse driver fixer file: Impulse Driver Fixer (149 downloads)
Close BetaFlight Configurator or turn off auto connect.
Run the ImpulseRC_Driver_Fixer.exe it will search for your flight controller.
Plug in your flight controller.
ImpulseRC will go through several phases. When It completes it may give you a warming about Chrome. Just click ok. Keep your usb cable connected to your quad. Open BetaFlight Configurator and you should be in DFU/BootLoader Mode.
The video below shows this process.
Option 3: Press Boot Button
Depending on your flight controller, there should be a boot button. This process involves physically pressing the boot button down while you plug your quad into your pc. However find your BetaFlight version, you should be able to google that a long with “boot button”. Example of a boot button below.
Option 4: Solder Boot Button
A boot button is simply a tactical switch, in most cases where there never is a button there is a label pads for boot. In the example below on a betaflight f4 2s, I had to solder a short on the boot button labeled pads in order to boot into boot loader / DFU mode.