I use Parallels to run Windows and have successfully upgraded my Windows 8.1Pro to Windows 10 using the Microsoft instructions. So far so good. i now want to make a WINDOWS 10 DVD for the future just in case I have to reinstall at some point. Plenty instructions on line, I have downloaded the Windows 10 Iso file to my Mac. I now need to burn it to DVD. I have tried using Disc Utility on the mac - open-end it, tried to drag the Iso file from desktop to the left hand pane in Disk utility as per instructions but it will not stay there for me to highlight then copy? The file is 4.08 Gb, my blank DVD is 4.7 Gb so big enough. What am I doing wrong? How can I get Yosemite Disk utility to accept the Windows 10 ISO for burning? Edited to add that the DVD drive is being recognised by Disk Utility. Thanks.