The standard video player in Aspire One is MPlayer - the Media Master is just another GUI to use mplayer.
But the MPlayer that cames standard in this Linux can't play some of the most common video codecs used on the internet video files (like DivX, XviD, H.264, etc) I don't know if it's a bug in libvacodec (used by MPlayer) or some sort of patent protection to avoid some codec licensing problems on some countries.
Anyway, if you want to play a more "uncommon" codec video file, you can "install" the video codecs available in official MPlayer site for download:
(get binary codec package for linux x86, decompress it somewhere and put the files (mostly dll's) in "/usr/lib/codecs/")
If you don't know how to do this, open the file manager, and in file menu you can open a terminal to type command lines.
Whenever a password is needed, it's the password you entered in the factory wizard of the first time you started the computer.
So if you downloaded a file say "essential-20071007.tar.bz2" you should do something like this:
tar xvfj Downloads/essential-20071007.tar.bz2
sudo mv essential-20071007/* /usr/lib/codecs/
or in case you want a more complete codec package:
get the file from:
tar xvfj Downloads/all-20071007.tar.bz2
sudo mv all-20071007/* /usr/lib/codecs/
now your MPlayer sould be able to play some more ccodec types, but unfortunately not the most common ones, so here you can get a new version of MPlayer that can play almost everyting (somewhat like VLC) files needed:
They are RPM packages made for Fedora Core 8 so you can install them on your One's Linux - you should follow by that order.
And to conclude some more command lines:
sudo ln -s Skin skins
sudo ln -s bluecurve default
And U'll have a new fully functional version of MPlayer with dozens of new skins available.
Right click on any of MPlayer's window and select skin browser to try them.
PS: If MPlayer starts complaining about a missing font (at the begining of playback), go to it's preferences (right click menu of MPlayer) and select this font:
Good MPlaying ;)