I am trying to make my entire ubuntu(12.04) OS with all the softwares installed to an ISO file so that It can be installed through Virtual box in another system . Could someone help me in this ?
You can use
It might be better instead to back up and restore your data, installed package list, and files.
That dumps the list of all packages installed on your system to /home/me/mypackages.list. Now, do a clean Ubuntu install on a new VM on your Virtualbox. Get /home/me/mypackages.list copied into that system.
On the new system,
Once that's done, you can selectively copy over the configurations and data from the original machine as well. If you've got apache, overwrite /etc/apache2 with the contents of /etc/apache2 from the old machine. Etc, etc, etc. DO NOT just blindly copy the entire contents of /etc from the old machine into the new machine - you'll give yourself problems if you do. You can just copy the contents of /home from the old machine into /home on the new machine, but you'll need to recreate the users and fix the permissions appropriately as you do. (You could, in theory, copy over /etc/passwd and /etc/shadow - or portions of them - directly, and in fact I do this kind of thing... but don't do that unless you know exactly what you're doing. You've been warned.)