This article explains how to change the playback speed of a song in Windows Media Player. This procedure works for Windows Media Player 12 on Windows 7, Windows 8.1, or Windows 10.
How to Change Video Playback Speed in Windows Media Player in Windows 10/11
Open a song. Switch the view mode from Library or Skin by going to View > Now Playing. If the WMP menu bar is not visible, use the keyboard shortcut Ctrl+M to enable it. You can even use Ctrl+3 to switch the view to Now Playing instantly without using the menu bar.
Right-click on the main screen and choose Enhancements > Playback Speed Settings.
In the Play speed settings screen that should now open, select Slow, Normal, or Fast to adjust the speed at which the audio/video should play. A value of 1 is for normal playback speed, while a lower or higher value will slow down or speed up the playback speed respectively.