How to Slow Down and Speed Up Video in Windows Movie Maker
You can change the speed of any clip in your Windows Movie Maker.
Change clip speed
1.In the timeline, select one clip you want to change the speed.
2.Click to enter the setting mode.
3.You can adjust the speed for your video here. Drag to right to speed up, and drag to left to slow down.
Then click “Return” to confirm your editing.
If the clip contains audio, playing the clip more slowly lowers the pitch of the audio and playing the clip faster raises the pitch. To preserve the original pitch of the audio, right-click the video clip and select "Detach Audio" and then it will auto moved to the audio track.
Change the speed of part of a clip
Any part of a clip can be sped up or slowed down, and the speed of any part will not interfere.
Select a location in a clip in the Timeline, and then click scissors to split it into two parts.
Click to enter the setting mode.
Use the slider to adjust the speed of each section by clicking it.
Part 1's speed
Part 2's speed
The speed of the copied video clip can also be adjusted and the two videos do not affect each other.