I just installed Windows 10 on a late 2015 iMac. Because I had a free upgrade from Windows 8 to Windows 10. The only way to install Windows 10 and activate it was to start with Windows 8 and bootcamp assistant, they upgrade to windows 8.1 and then to Windows 10. Everything looks good bit I do have a yellow triangle next to the bluetooth driver. I there a way to download the windows 10 bootcamp drivers and rerun the install from windows?