can anyone tell me how to upgrade from ubuntu 12.04 to 12.10 from a Cd
Prior to Ubuntu 12.10 you can able to upgrade your Ubuntu OS with the help of Ubuntu Alternate CD. But with the release of Ubuntu 12.10 Steve Langasek from Canonical announced on August 27th, a proposal to drop the Alternate CD ISO images starting with the upcoming Ubuntu 12.10 (Quantal Quetzal) operating system. On August 30th, the Alternate CDs were gone from the daily builds and will not be available at the launch of Ubuntu 12.10 Beta 1. For more information your can go through following link
In case you want to upgrade from the disk which you have downloaded from the internet then follow below steps
Step 1. Boot with Ubuntu 12.10 Disk
Step 2. Select Install Ubuntu Option
Step 3. On the installation type screen choose Upgrade Ubuntu 12.04.1 LTS to Ubuntu 12.10
In this option "Document, music and other personal files will be kept. Installed softwares will be kept where possible. System-wide settings will be cleared." Kindly Note that as a safer side kindly take the backup of your data.
In case you want to update your Ubuntu OS using update manager then follow below post
Well, there's no CD anymore, but here's a DVD image: http://www.ubuntu.com/download/desktop
After that you can burn it to a DVD, then put the disk in. Then look in the box at the bottom of "software sources" under "installable CD/DVD".