Question: how to open mkv file?
Answer: To watch an MKV file using VLC, right-click the MKV file, point to “Open With,” and then choose “VLC Media Player.” To make VLC the default player for MKV files so that you can just double-click a file when you want to watch a video, right-click any MKV file, point to “Open With,” and then click “Choose Another App.”