When you plug in your ESP32 to your PC, do you hear a sound? If not, try a different USB cable. Does Windows say anything about installing drivers failed? You might need to manually install the drivers. If you open the device manager of windows are there any USB devices listed (after you plugged in the ESP32) that have no drivers installed? Then you most likely need to manually install FTDI (USBtoSerial) drivers. I needed to install separate drivers for the onboard USB of my ESP32. In my case it was for a CP2102 chip. You can find the drivers here: ESP32.net. Did you try to use a different USB cable?And last, some ESP32 boards need to be set manually into bootloader mode. On my board that would be pressing the RESET button and keep it hold, then press the USR button and keep it hold, then release the RESET button, then release the USR button. Might be different for your board.