Could not download all repository indexes problem: Failed to fetch cdrom

Hi,
I am a rookie Ubuntu user and when trying to update packages I get this error:

 Failed to fetch cdrom:[Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1)]/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
Failed to fetch cdrom:[Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1)]/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
Some index files failed to download, they have been ignored, or old ones used instead.

I then tried to upgrade with the terminal and here is what it reads:

~$ sudo apt-get update

Ign cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy Release.gpg
Ign cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy/main Translation-en_US
Ign cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy/restricted Translation-en_US
Ign cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy Release
Ign cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy/main Packages
Ign cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy/restricted Packages
Err cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy/main Packages
  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Err cdrom://Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1) hardy/restricted Packages
  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Hit http://us.archive.ubuntu.com hardy Release.gpg
Ign http://us.archive.ubuntu.com hardy/main Translation-en_US
Hit http://security.ubuntu.com hardy-security Release.gpg
Ign http://security.ubuntu.com hardy-security/main Translation-en_US
Ign http://us.archive.ubuntu.com hardy/restricted Translation-en_US
Ign http://us.archive.ubuntu.com hardy/universe Translation-en_US
Ign http://us.archive.ubuntu.com hardy/multiverse Translation-en_US
Hit http://us.archive.ubuntu.com hardy-updates Release.gpg
Ign http://us.archive.ubuntu.com hardy-updates/main Translation-en_US
Ign http://us.archive.ubuntu.com hardy-updates/restricted Translation-en_US
Ign http://us.archive.ubuntu.com hardy-updates/universe Translation-en_US
Ign http://security.ubuntu.com hardy-security/restricted Translation-en_US
Ign http://security.ubuntu.com hardy-security/universe Translation-en_US
Ign http://security.ubuntu.com hardy-security/multiverse Translation-en_US
Hit http://security.ubuntu.com hardy-security Release
Ign http://us.archive.ubuntu.com hardy-updates/multiverse Translation-en_US
Hit http://us.archive.ubuntu.com hardy-backports Release.gpg
Ign http://us.archive.ubuntu.com hardy-backports/main Translation-en_US
Ign http://us.archive.ubuntu.com hardy-backports/restricted Translation-en_US
Ign http://us.archive.ubuntu.com hardy-backports/universe Translation-en_US
Hit http://security.ubuntu.com hardy-security/main Packages
Ign http://us.archive.ubuntu.com hardy-backports/multiverse Translation-en_US
Hit http://us.archive.ubuntu.com hardy Release
Hit http://us.archive.ubuntu.com hardy-updates Release
Hit http://us.archive.ubuntu.com hardy-backports Release
Hit http://us.archive.ubuntu.com hardy/main Packages
Hit http://us.archive.ubuntu.com hardy/restricted Packages
Hit http://us.archive.ubuntu.com hardy/main Sources
Hit http://us.archive.ubuntu.com hardy/restricted Sources
Hit http://us.archive.ubuntu.com hardy/universe Packages
Hit http://us.archive.ubuntu.com hardy/universe Sources
Hit http://us.archive.ubuntu.com hardy/multiverse Packages
Hit http://us.archive.ubuntu.com hardy/multiverse Sources
Hit http://us.archive.ubuntu.com hardy-updates/main Packages
Hit http://us.archive.ubuntu.com hardy-updates/restricted Packages
Hit http://us.archive.ubuntu.com hardy-updates/main Sources
Hit http://security.ubuntu.com hardy-security/restricted Packages
Hit http://security.ubuntu.com hardy-security/main Sources
Hit http://security.ubuntu.com hardy-security/restricted Sources
Hit http://security.ubuntu.com hardy-security/universe Packages
Hit http://security.ubuntu.com hardy-security/universe Sources
Hit http://security.ubuntu.com hardy-security/multiverse Packages
Hit http://security.ubuntu.com hardy-security/multiverse Sources
Hit http://us.archive.ubuntu.com hardy-updates/restricted Sources
Hit http://us.archive.ubuntu.com hardy-updates/universe Packages
Hit http://us.archive.ubuntu.com hardy-updates/universe Sources
Hit http://us.archive.ubuntu.com hardy-updates/multiverse Packages
Hit http://us.archive.ubuntu.com hardy-updates/multiverse Sources
Hit http://us.archive.ubuntu.com hardy-backports/main Packages
Hit http://us.archive.ubuntu.com hardy-backports/restricted Packages
Hit http://us.archive.ubuntu.com hardy-backports/universe Packages
Hit http://us.archive.ubuntu.com hardy-backports/multiverse Packages
Hit http://archive.canonical.com hardy Release.gpg
Ign http://archive.canonical.com hardy/partner Translation-en_US
Hit http://archive.canonical.com hardy Release
Hit http://archive.canonical.com hardy/partner Packages
Hit http://archive.canonical.com hardy/partner Sources
W: Failed to fetch cdrom:[Ubuntu 8.04.1 _Hardy Heron_ - Release i386 (20080702.1)]/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 8.04.1 _Hardy Heron_ - Release i386 (20080702.1)]/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.

I don't understand what to do now! Any help would really be appreciated.