Videos that are posted online can be viewed within PowerPoint 2010 if you can copy the embedded html code. The steps are very simple.
First Step: Right click the video from a YouTube site and choose “Copy Embed html”.
Second Step: Go to the slide within PowerPoint and click the Insert tab–>Video–>Video from Web Site.
Third Step: Paste the html embed code.
Fourth Step: View slide show and click the video play button when presenting the PowerPoint presentation. It usually takes about 3-5 seconds once you advance to the slide for the play button to become available.
Note: You must have PowerPoint 2010, Internet connection, and the video must still be posted online. * It will not work with Broadcast Slideshow feature.