To use Windows Media Player to playback the record file from DVR, please use the K-Lite_Codec_Pack_895_Full.exe install the K-Lite codec package. Please Note: The DVR programming must be set to "Composite" in order to create files viewable on third party players. The default setting for all SD4mX DVRs is "Seperate" recording, for playback with the dedicated video player included at no cost (AVPlayer).