Codec packs are dangerous if chosen poorly. The only safe, non-malicious pack for 64-bit Windows 10 is the K-Lite Codec Pack (Basic or Standard).
Important Note: The legacy Windows Media Player does not support DVD movie playback natively on Windows 10. Microsoft removed the MPEG-2 decoder required to play commercial DVDs. windows media player windows 10 64-bit
Solution: If you need to play DVDs, do not use Windows Media Player. Instead, download VLC Media Player (free and open source), which plays DVDs without needing extra codecs. Codec packs are dangerous if chosen poorly
The Good:
The Bad:
If you cannot play modern iPhone videos (HEIC/HEVC) or MKV files, you need the official codec. The Good: