Hello. Congratulations on making the transition. To play movie files, install the w32codecs package on your system, and then applications such as Totem movie player will be able to play them (most of them anyway). The package mplayer is also very good for viewing movie files, and often is required for viewing embedded movie files on the internet (mplayer does use a lot of system resources, however; so, if your system is weak, it can cause crashes.) For just viewing movie files that exist on your hard drive, Totem is good. I've also heard that Kaffeine is good (I can't really vouch for this, though). Anyway, to get the package w32codecs installed, add the Debian Multimedia repositories to your sources.list (this repository also has mplayer, realplayer, acroread, etc). For details on this, see http://www.debiantutorials.org/content/view/86/114/I have several movie files from my previous operating system (Windows). I want to play those files on Debian. What package should I install? Thanks.
Good luck! Mark