I have downloaded all the drivers and I've used impulse rc tool as well as zadig. I can get it to connect through COM7 but I can't get it into DFU mode. I have restarted everything several times and I am shorting the boot pins before plugging in and the led isn't flashing so I know it's in boot mode. When I open zadig and click list all devices it doesn't list stm32 bootloader only cp2102 sub to uart bridge controller. I have tried all the driver options and like I said I can get it to connect through com7 then it says my firmware is out of date and I need to upgrade so I choose spracingf3 and the latest version then load firmware and when I try to flash it says no response from bootloader, programming failed. I have tried every solution I can find online and I've had no luck. I'm trying to do this for a friend. I've done this process on a couple other quads and I got into dfu mode with zadig no problem. I'd appreciate any help.