Open the slide that you want to put the screen recording on.
On the Insert tab of the ribbon, select Screen Recording.
On the Control Dock, choose Select Area (or if you want to select the entire screen for recording, press Windows logo key+Shift+F). You’ll see the cross-haired cursor . Select and drag to select the area of the screen you want to record. The minimum size area you can record is 64×64 pixels. Tip: PowerPoint automatically records the audio and the mouse pointer, so by default those options are selected on the control dock. To turn them off, deselect Audio and Record Pointer.
Select Record. Use Pause as needed and Stop when you’re done. Note: 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.
Your video is added to the slide. Right-click the video frame, select the Start icon and pick how you want your video to start: In Click Sequence, Automatically, or When Clicked On.
You can change the look of the video by right-clicking the video frame, select the Style icon, and pick another shape.
Save your screen recording as a separate file
Right-click the video frame, and select Save Media as.
In the Save Media as box, choose a folder, and in the File name box, type a name.
Trim your video
Right-click the video frame, and select Trim.
To determine where you want to trim your video footage, in the Trim Video box, select Play.
When you reach the point where you want to make the cut, select Pause. 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, select 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.