I'm sorry to hear that.Personally I had the issue on a Nucleo-F411RE board, where the issue was solved following these steps.Before solving it, the STM32 ST-LINK Utility showed this in the settings window after pressing the refresh button.

I had the same issue, where WIndows 7 works fine, but Windows 10 doesn't.But there is a solution =)Uninstall STM32 ST-LINK Utility.While your Dev Board is connected, uninstall and delete the "STMicroelectronics STLink Virtual COM Port (COMxx)" device...