Réponse en Anglais svp
Lets see how good my French is
You currently use windows.
You want advise on a GNU/Linux distribution to try - you want to be able to watch movies, play CD/DVD and surf the internet.
This is not a problem... any major distro will do that for you out of the box.
If you want to play restricted formats (mp3, avi) or encrypted files (practically any commercial DVD) you will have some issues to address. However, some less-scrupusous distros which enable a great deal of this stuff by default are PCLinuxOS, Linux Mint, SimplyMepis and so on.
Hopefully you can read English
the rules here require posting in a common language so we can all, in principle, share your solutions. The mods have chosen English.