What is the best MP4 codec for WMP?

The wrong codec can also cause problems with other codecs.

Media Player

To See if a Fix is Available

If it involves a crash.

In Control Panel (and select Classic view in the left hand pane) choose Problem Reports and Solutions (type problem in Start's search box), go to Problem History, right click your error and choose Check For Solution.

You may also right click and choose Details for more info. **Post those details here.**The Fault Module Name is the important information.

Get the Error Code

When you try to play the file and it can't be played you should get a dialog offering Web Help. This contains the error details. Post the web address it takes you too so we can read it too.

To See What Codec is being Used

While playing the file right click it in the Now Playing pane and choose Properties. On the file tab will list the codecs being used. If Now Playing pane is not showing right click Now Playing on the command bar and tick Show List Pane.

Disable Codecs

Download Autoruns from http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx

Start the program and click Options menu - Filter Options and tick Hide Microsoft entries.

If you have identified a codec from first step disable that one. Else go to the Codecs tab. Untick one by one and see if you can play the file. Restart Media Player before trying to play the file.

Media Player Fixit

Click Play games, music or sounds, pictures or video and see the Fix Windows Media Player video, and other media or library issues Fixit.

http://support.microsoft.com/mats/video_freezes_or_crashes/en-us

and

http://support.microsoft.com/mats/windows_media_player_diagnostic/en-us

For the full list visit

http://support.microsoft.com/fixit/en-us

When you choose to download it, choose the option to run on another computer. Then you can save it to your harddisk in a folder. Open the folder, open the folder Fix it Portable, and run Launch Fix It. It will contain all 27 Fixits.

Registering Media Player Components

Also try registering Media Player components and deleting the database.

Start - All Programs - Accessories - Right click Command Prompt and choose Run As Administrator. Type (or copy and paste by right clicking in the Command Prompt window and choosing Paste).

SC Stop WMPNetworkSvc

regsvr32 "C:\Program Files\Windows Media Player\mpvis.DLL"

regsvr32 "C:\Program Files\Windows Media Player\wmpband.dll"

regsvr32 "C:\Program Files\Windows Media Player\wmpsyncmgr.dll"

regsvr32 "C:\Program Files\Windows Media Player\wmpnssci.dll"

"C:\Program Files\Windows Media Player\w1mlaunch.exe" /reg

"C:\Program Files\Windows Media Player\wmpconfig.exe" /reg

"C:\Program Files\Windows Media Player\wmpnetwk.exe" /reg

"C:\Program Files\Windows Media Player\wmpshare.exe" /reg

Del "%userprofile%\CurrentDatabase_*.wmdb" "%userprofile%\LocalMLS_*.wmdb" /a /s

sc start WMPNetworkSvc

Download Codecs Automatically

In Media Player right click Now Playing tab on the command bar - More Options - Player tab - Download Codecs Automatically.

Install A Codec Pack

It may be using an unusual codec (most are MS and built in to windows). See http://en.wikipedia.org/wiki/K-Lite_Codec_Pack#Supported_file_formats for  other codecs.

Setting Media Player as the Default Player

In Control Panel (and select Classic view in the left hand pane) choose Default Programs. Choose Media Player under both Set Your Default Programs and Set Program Access and Computer Defaults. The other two options are for setting what plays a specific file type and what happens when you insert media.

Maybe because I disabled some of the decoders.

Maybe you could tell me which decoders I need for MP4 to work in WMP?

K-lite codec pack is free and safe, and it includes almost all video codec and audio codec.

I installed K-lite and set the default of MP4 files to Windows Media Player.

Didn't help, WMP still doesn't recognize MP4 files and plays it with problems just like before I installed K-lite.

Thanks anyway, though.

Thank you AmiePaschal!

Just one question, is K-lite a player in itself, or is it just a codec that will enable me to play any video file type with WMP and VLC?

Thank again!