OK, so you bought a PC. You installed PowerPoint on it. But it fails to show the movies embedded in the PowerPoint lecture files that you want to and need to see. The links below attempt to provide what Microsoft refuses to deal with to make PowerPoint on the PC fully capable of showing multimedia files. I remember hearing from PC users that Mac folks should buy a "real" computer that does Windoze. Back at you! Buy a real computer that can handle embedded movies...buy a Mac! If you are a Mac user, you don't even need this page...these videos are the ones embedded in the PowerPoint lecture files that work just fine on your Mac and show the videos in context with the rest of the lecture material.
The files linked below appear to download very slowly to PCs...and a PC does not indicate that a download is in progress...but, if you are patient, a new window will open and the file might play. Please note: The Windoze Media Player routinely acts like it can play media, but it generally fails to display .mov .mpg and .avi files. Installing QuickTime for the PC and/or Real Player may solve the problem. You may need to use Firefox as a browser to avoid defaulting to the Windoze Media Player. There again, if you want your internet browser to follow W3C standards, you should use Firefox rather than Internet Explorer anyway.
The files linked below are from highly reputable educational sources as indicated by the URLs associated with each link. I hope that your PC is able to show these standard media files in your web browser, since PowerPoint 2010 cannot. I am sorry you have to view these video clips out of the context of the lecture with which they are associated.
Physarum cyclosis
http://botit.botany.wisc.edu/courses/img/Botany_130/Movies/Slime_mold.mov
Amoeba cyclosis
http://videoserver.magnet.fsu.edu/micd/pondscum/protozoa/amoeba/mpeg/amoeba01ob.mpg
Elodea cyclosis (longer)
http://www.microscopy-uk.org.uk/mag/imgnov00/cycloa3i.avi
Elodea cyclosis (shorter)
http://botit.botany.wisc.edu/courses/img/Botany_130/Movies/Elodea_Cyclosis.mov
Lumbriculus circulation
http://scied.fullerton.edu/VIDA/VIDAImages/U2M5Lumbriculus/F00005.html