In Windows 7 system, its own Windows Media Player media player version is 12, Windows Media Player is referred to as WMP, WMP is mainly for common media formats, such as WMV, MP3, WAV, AVI and other media files, and it also Taking into account the heavy responsibility of streaming media playback, many video live broadcasts are WMP to watch. In all versions of Windows, WMP 12 is the most powerful, it can effectively manage your music, video, pictures and recorded TV programs, with the help of Windows7 media library, we can range in the home network Sharing data inside is very convenient. Moreover, WMP12 supports playback of HD format video, which is much more than the video format supported by WMP. Of course, compared with other professional players, there is still a certain gap. However, in the Windows Media Player media player in the Windows 7 RC version, there are a lot of problems when playing HD video in mkv format, the playback is not smooth, the subtitles cannot be loaded, and cannot be reversed. Microsoft said that this problem is most likely caused by poor compatibility between the decoder and Windows 7. It is recommended that he try to replace the decoder. Then this problem is mainly in the decoder of Windows 7 RC, the problem is found, the solution is also simple — — replace the self-contained with other decoders. However, it is easy to say, the actual operation still takes a lot of effort, the operation needs to be modified by modifying the registry. Note: The following operation is only for the case where WMP 12 uses a third-party decoder when playing local video files; modifying the registry editor is risky, please pay attention to backup. 1. Start Registry Editor and navigate to: HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\DirectShow\\Preferred 2. Right click on “Preferred”, select “Permissions” 3. Click on “Advanced at the bottom right of the window Advanced)”, then go to the "Owner" label, in the "Order to ” box, select “Administrators”, check the box below to replace all subcontainers and objects. "Replace Owner on subcontainers and objects" & rdquo;, click & ldquo; OK & rdquo; make the operation take effect. 4. Go back to the "Permissions" window, in the "Security" box above, select "Administrators", and then check the "Controls" permission in the "Administrators" tab below. "Allow" . This way you can modify the Preferred item of the registry. 5. Then find these two items in the right box: {e06d8026-db46-11cf-b4d1-00805f6cbbea} {31435641-0000-0010-8000-00AA00389B71} Double-click them respectively to bring up the "Edit String" dialog In the box, fill in the data value with the decoder CLSid (class identifier) you wish to use. The following are the CLSids of some commonly used decoders: FFDShow - {04FE9017-F873-410E-871E-AB91661A4EF7} MPCVideoDecoder - {008BAC12-FBAF-497B-9670-BC6F6FBAE2C4} COREAVC - {09571A4B-F1FE-4C60-9760-DE6D310C7C31} windows 7 Restart your computer when you are done.