First thing you have to do is to active the developer option on the top menu. By default you have something similar to this image.

So, to add the developer option, click on the office Icon on the top left of your screen as shown here

Then, click on the powerpoint option as highlighted in yellow in the image above.

You will window will pop up looks like this

Click on Popular then make sure to check the “Show Developer tab in the Ribbon“, Then Click Ok

Now, the Developer option will show in the ribbon “the menu” near view. Click on it. You should see these options shown in the image below.

Click on the icon highlighted in yellow. A new window will popup looks like this image. Scroll almost all the way down until you find Shockwave Flash Object as shown bellow.

Choose Shockwave Flash Object then click ok.

Now, draw any square in the powerpoint slide. You can do this, but dragging the mouse pointer. This is adjustable so don’t worry about the size of the video now. You should get something similar to this.

Then, Right click on the square or rectangle you just drawn and click on Properties.

The properties of the video will come up. Scroll down until you find Movie as shown bellow.

Now go to youtube and copy the link of the video you want to add to the slide.

Go back to your powerpoint and paste the link as shown below.

Here you are to do a little bit of work.

A. Delete watch?

B. Delete = and replace it with /

The link should look like this

Close this window and go back to your powerpoint and click on the slideshow to see your final product. End the slide show and adjust the size of the video whatever you like.

Remember, you always can go back to video properties and stop looping, or stop automatic play and many other options.