I am not sure what causes people to need a different driver than the arduino supplied drivers. I have tried on windows 7,8,and 10 and the official have always worked even on different machines. I wish I could figure that out some people haven’t had any experience installing drivers and that really frustrates them. It could be the boards but it doesn’t make sense that the same exact board gets flashed on my windows 10 machine with arduino drivers and then on a different machine needs different drivers. I’m wondering if it is the motherboard usb chipsets or maybe a different driver slightly conflicting or something. Thanks for the report though, I need to do a post with common connection issues and list these drivers and things.