You can check what driver is actually in use.
To do that you would:
- connect the board to the computer
- (eject safely if needed)
- hit upload, wait for it to fail
- find the device in “devices and printers” or the device manager. (It will be called “STM32 BOOTLOADER”)
- right-click and select properties, then “drivers”
- The driver should be WinUSB if I remember correctly. If it is something else, then that something else is probably what is interfering.