please help me! Error message while updating my ubuntu 8.04

[linux_beginner]

Hi!
i've a problem when i did try to update my ubuntu 8.04 to 8.10 and i got that message shown in the attached screenshot4 file

W:Failed to fetch cdrom:[Ubuntu 8.04 _Hardy Heron_ - Release i386 (20080408)]/dists/Hardy/main/binary-i386/Packages.gz Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
, W:Failed to fetch cdrom:[Ubuntu 8.04 _Hardy Heron_ - Release i386 (20080408)]/dists/Hardy/restricted/binary-i386/Packages.gz Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
, E:Some index files failed to download, they have been ignored, or old ones used instead.
also when i trie dto add hardy cd to source list igot error emssage again shown in the attached screenshot5 file
pleae could someone tell me what i should do to fix this problem and update my ubutnu 8.04 ?

[Pumalite]

Administration>Software Sources>Tick off CD-ROM

[linux_beginner]

it works now! thnx Pumalite
i ve another question please!!
now i launched the upgrade tool and it's in the "Getting New packages" step and the problem is my slow connection(dsl connection speed <256 ko/s) and it says "about 11 Hours remaining " wich means i can't let my pc all teh time turned on! so can i download or use upgrade tool time to time (for ex ;i stop it now then tomorrow i continue ? am i able to do that?
thnx !

[linux_beginner]

any answer??!!