Here are the steps for creating a screen recording in PowerPoint.
1. Make sure that the PowerPoint that you want to record is open.
2. Open the slide that you want to put the screen recording on.
3. On the Insert tab, select Screen Recording.
4. On the Control Dock, click Select Area.
5. Click Record (Windows logo key+Shift+R).
Tip: Unless you pin the Control Dock to the screen, it will slide up into the margin while you record. To make the unpinned Control Dock reappear, point the mouse cursor at the top of the screen.
6. To control your recording:
a. Click Pause to temporarily stop the recording (Windows logo key+Shift+R).
b. Click Record to resume recording (Windows logo key+Shift+R).
c. Click Stop to end your recording (Windows logo key+Shift+Q) (shown below).
7. When you are finished recording, save your presentation: File > Save. The recording is now embedded on the slide you selected in step.
a. To save the recording itself as a separate file on your computer, right-click the picture on the slide that represents the recording, and select Save Media as. In the Save Media As dialog box, specify a file name and folder location, then click Save.
8. Set Your Video 'Start' Settings
a. Right-click the video frame, click Start, and pick how you want your video to start in your presentation; automatically when a slide appears, or when you click the mouse.
9. Trim your video
a. Right-click the video frame and click Trim.
b. To determine where you want to trim your video footage, in the Trim Video box, click Play.
c. When you reach the point where you want to make the cut, click Pause.
Tip: Use the Next Frame and Previous Frame buttons to specify precise timing.
Do one or more of the following:
-To trim the beginning of the clip, click the start point (shown in the image below as a green marker). When you see the two-headed arrow, drag the arrow to the desired starting position for the video.
-To trim the end of the clip, click the end point (shown in the image above as a red marker). When you see the two-headed arrow, drag the arrow to the desired ending position for the video.