How to install Mplayer

Please Note: This only works for Xandros 4.

Download Mplayer

1. Uncompress the file.
2. Open an administrative file manager from Applications -> System -> Administrator Tools -> Xandros File Manager (Administrator)
3. Browse to the folder in which you uncompressed the files.
4. Go to Tools open console.
5. In the console run dpkg -i *.deb
6. Leave the console open for now.
7. Open Xandros Networks.
8. Go to Edit -> Set Application Sources
9. Make sure both the Xandros Repository and the Debian Unsupported Repository are enabled.
10. Once the package list is refreshed close Xandros Networks.
11. In the console type in apt-get install -f

Enjoy!

Thanks to BoyLinux & Davepet for the information provided and posted in the forums.