I used my Arduino Uno v3 for some time and it had no problem on windows 8.1. Now I want to use it on 10 but it says it can’t open COMx. When i checked in Device Mangaer, windows 10 had no Ports menu item. In the IDE I couldn’t select any Port in the Tools menu, just the Board. I tested it on another laptop with windows 7 and it had the same problem. I don’t think the OS is the problem. But what’s the problem then?