Ubuntu requires CD for software (installs and updates)

If when attempting to update software or install new software in Ubuntu you find yourself being asked to insert the installation/live CD or if you find the following errors while trying to update your sources the following should help fix this error.

W: Failed to fetch cdrom://Ubuntu 11.10 _Oneiric Ocelot_ – Release amd64 (20111012)/dists/oneiric/main/binary-i386/Packages […]

How To Fix “Fatal server error: no screens found” | Ubuntu

If you’re running off a live USB disk or changing your graphics card the error below might appear when Xorg is looking for the wrong drivers or device. You might also get this error while using the Nvidia drivers, I found however this was caused by some of the extra options added into the […]