FC2Video

Make sure you’re using the most recent WMP 12 to play H.264 file. Or you can install K-Lite codec pack to extend the playback ability of WMP and this video will show you how to.
Install K-Lite codec: https://codecguide.com/download_kl.htm
There is the text-based tutorial to play H.264 files:
https://www.videoconverterfactory.com/tips/h264-codec-windows-media-player.html