If the file is already small enough to fit your target blank dvd, try burning it with a free burning program called ImgBurn. www.imgburn.com
Follow this guide for burning a dvd-video folder (Video_TS) to a dvd using ImgBurn: http://forum.imgburn.com/index.php?showtopic=4632
ImgBurn will also show you the make and model drive you have, so it might be helpful for us to know that. Look on the right side of the main window in ImgBurn and click on the Device tab.
If you have a problem with the burn, post the burn log from ImgBurn here in your thread. You can find that by clicking Help within ImgBurn, then click on the ImgBurn Logs entry.