I am creating the custom operating system using the ubuntu 12.04. When ubuntu login from the light dm -- it shows ubuntu desktop . i need to change to the my os name. I need to replace the ambaince dark icon to fs icon by default for all the login and live cd. How to permanentely change the os name It should not change even the customer update the operating system too.

I am using the remastersys. I am looking to develop the new distro. like mint ,, If i had an breif explanation of the creation of the repository and maintaining the updates . it will be more helpfull. Kindly provind the link for creating the full fledged os based on the ubuntu .. like mint, Snowlinux, etc did..

replace the grub with burg for default installation

If remastersys is not good . then provide me some other tool to create . I am not having the high speed internet