Windows Media Player is the built-in media player for Windows that allows users to play multimedia files. While I wouldn't call most Windows applications “best in class”, Windows Media players are still an exception. It is one of the cleanest and obviously safest multimedia tools.
For all extensions and codecs supported by the media player, WMP is known to be nearly bug-free, however users have reported an issue where they get the error:
Windows Media Player encountered a problem playing the file.
This error can be file or system specific. We will solve it step by step to isolate all possibilities.
Solution 1] Reinstall Windows Media Player via Features
Now that we have isolated the problem with the system in the solution above, we could try to reinstall the Windows Media Player application.
1] Search Enable or disable Windows features in the Windows 10 search box.
2] Now, click on the search result to open it Windows features.
3] Expand the file Multimedia functions program and you will find the Windows Media Player.
4] Deselect Windows Media Player and click OK.
5] Restart your computer and Windows Media Player will reinstall themselves, provided the system is connected to the Internet.
Solution 2] Disable the Windows Media Player Network Sharing Service
1] Press Win + R to open the Run window and type the command services.msc. Press Enter to open the Services window.
2] In the list of services, find the file Windows Media Player Network Sharing Service.
3] Right-click on that service and click Property.
4] Change the file Start type to Disabled in the drop-down menu. Click on To apply and so ok.
5] Restart the system.
Solution 3] Check the file extension
Windows Media Player is designed to play all legitimate files. For instance. The .mp4 and .wmv files work well with Windows Media Player. However, some extensions (such as FLV) and codecs do not support WMP. One of the reasons these files are not compatible with the Windows built-in media player is that they are generally downloaded from websites such as Youtube using third party tools.
These files can be played with third party media players like VLC; however, it is highly recommended not to use them as they damage the speakers. Also, installing VLC voids the warranty for many laptop brands.
Solution 4] Update Windows
If the file extension is supported by Windows Media Player and all files of that extension are not working, it could be assumed that there may be a system conflict. We could update Windows to fix the same problem.
1] Click the Start button and then the gear symbol to open the Settings page.
2] Go to Updates and Security, then click Update Now.
3] After the update is complete, reboot the system.
Check if it helps with the problem.
Solution 5] Temporarily disable your antivirus software
Antivirus software can prevent Windows Media Player from opening a file if it suspects it may be malware. To isolate this possibility, open your antivirus program and disable it. Reboot the system. It may be reactivated later.
Solution 6] Check for interference from third party programs
Third-party programs can cause problems when trying to start media files if they interfere with the codecs. This is especially true if you have free third-party media players installed on your system.
1] Press Win + R to open the Run window and type the command control panel. Press Enter to open the Control Panel.
2] Go to Programs and Features and organize the program list by installation date.
3] Check for recently installed problematic programs and remove them if necessary.
We believe that when these solutions are exhausted, the problem will be solved.