From: Jose B 28 April at 01:49
When installing Linux on your Windows machine using Wubi, your Linux installation will not have access through the synaptic package manager to the Ubuntu Restricted Extras; also you will not be able to install them through the web page either.
What I did to get around this is:
1. I opened the terminal (Applications-Accessories-Terminal)
2. At the prompt type: $ sudo aptget ubuntu-restricted-extras
– This will install the restricted extras packages
3. type: sudo /usr/share/doc/libdvdread4/install-css.sh
– This will install dvd support to your linux system that was installed through Wubi
Now you will have a fully functional Linux system. This was tried on a Windows 7 machine.