You'll probably need to either convert the files, or use something else to handle the burning. I'm sure there are some free burning apps that would handle the task.
Thanks - I've waded through a bunch of free ones -no success yetAccording to a quick perusal of the links below, Win DVD Maker doesn't support mkv files. Finding a good converter seems to be the solution. Finding the right solution may just take a bit of research and a spindle of DVDs (or a pack of DVD-RWs) to get the desired results. Here are the links:
http://www.sevenforums.com/music-pictures-video/102735-windows7-dvd-maker-mkv-files.html
Cannot burn MKV files using Windows DVD Maker - Microsoft Answers
windows dvd maker mkv - Google Search
Thanks but none of these work. Things like DVDFlick and Imgburn don't recognise and others cost $I turned up a bunch of info with a quick Google Search, including a guide on a renowned site.
Convert MKV to DVD with freeware - AfterDawn: Guides