View source for Nagy-videos-2009:Notes

These presentations all contain xvid-encoded and embedded videos. They can be played back flawlessly with mplayer on all platforms, or with some platform-native player. Windows needs Koepi's codec (free) to play them back from ithin Powerpoint. Or xvid - it also has a free verion.
http://www.koepi.info/xvid.html

the original format of the videos I make/made is ogv - this contains uncompressed frames, yet relatively small.
They can be played back with mplayer too, for Win there is a (free!) codec here as well (for directshow-based players):
http://www.xiph.org/dshow/

Please find the list of files here:
http://www.orl.szote.u-szeged.hu/~attila/presentations.html

If the embedded videos do not work (in MS Powerpoint) then deleting them from the presentation and re-inserting them should solve the problem. (After having made sure that there is a working directshow-compatible divx/xvid codec on that machine.)