A long time ago on an operating system far from Windows 10, there was a video editor called Movie Maker. At some point, someone decided a video editor was too much for most people to handle, and it was removed from Windows. You could add it back, if you were ambitious, but most people did not. Movie Maker is no longer supported by Microsoft. Now there is no built-in video editor on a new Windows computer. There is suppose to be something called Story Remix in Windows 10, but at this point, it is more difficult to acquire than Movie Maker ever was.
Yesterday I needed to make a quick video. I was given two videos. Each video was about six minutes long. I needed to chop out two minutes from the middle of each video and my computer had no video editing software. All my computers have PowerPoint and it turns out, that was all I needed.
I opened a new presentation in PowerPoint and made three blank slides with black backgrounds. The first slide would be my introductory slide and the next two slides would each contain a two minute video. By making the background black, I eliminated any bright edges that might happen if my imported video did not completely fill the slide.
I typed Movie Title into the first slide and went to the second slide to insert the first video.
From the Insert menu I clicked the Video button and added video from my PC.
PowerPoint shows the first frame of the video in the slide, but since this video starts with a black screen, there is no preview on slide two. 
In the Playback tab, select “Automatically” as the Start option. The difficult step in the entire process is editing the video so that the only part I want remains. To edit the timeline of the video, click the Trim Video icon.
This will pop up a video player with trim tools.
The green slider is positioned at the beginning of the clip and the red slider is moved to the end of the clip. Fine adjustments can be made in the Start Time and End Time boxes. Use the play button to preview the new trimmed video. When everything plays perfect, click OK.
Now the second slide shows the trimmed version of the video.
On slide three, I repeated the Insert process for the second video and trimmed it.
The segment I needed from the second video is closer to the middle of the full video. Notice the location of the green and red sliders.
When the second video was trimmed, the video editing portion of the project was complete. 
Since this is PowerPoint, I can easily add text and pictures to my first slide to introduce the videos that followed.
There is one last step before saving this file as a video. Go through each non-video slide and set a playback time. The first slide is not a video slide, so the auto-advance time was adjusted to 5 seconds.
The auto-advance times for slides with videos will automatically match the play duration of the video.
The final step is saving the PowerPoint as a video. Click File – Save As and select MP4 from the dropdown box.
Done – https://youtu.be/gkhIe-RosRw