About Windows Media Format 9 Runtime Files
All Windows Media Format video and audio streams are in mp3 format, which are virtually compressed. They use the LZW (LZO) compression algorithm, so you will be able to notice a significant speed increase with conversion. Furthermore, Windows Media Format has two versions: Windows Media Player version and Windows Media Encoder. Windows Media Player version is compatible with almost all operating systems, while Windows Media Encoder requires software that is capable of decompressing the compressed streams.
The good thing about Windows Media Player is that it converts video and audio streams without quality loss. On the other hand, Windows Media Encoder requires high-end hardware because the decompression algorithms need the use of many audio codecs. Another downside is that it does not support audio fast forwarding or simultaneous buffering, which means that Windows Media Encoder cannot operate as fast as Windows Media Player. However, this can be easily fixed using third-party software that offers great compatibility with different operating systems.