set@set:~/www/gtdl$ sudo apt-get install chromium-browser
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  nvidia-settings-experimental-304 python-xkit screen-resolution-extra
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  chromium-browser-l10n chromium-codecs-ffmpeg-extra
Recommended packages:
  pepperflashplugin-nonfree
The following NEW packages will be installed:
  chromium-browser chromium-browser-l10n chromium-codecs-ffmpeg-extra
0 upgraded, 3 newly installed, 0 to remove and 493 not upgraded.
Need to get 42.2 MB of archives.
After this operation, 171 MB of additional disk space will be used.
Do you want to continue [Y/n]?
WARNING: The following packages cannot be authenticated!
  chromium-codecs-ffmpeg-extra chromium-browser chromium-browser-l10n
Install these packages without verification [y/N]? y
Err http://archive.ubuntu.com/ubuntu/ quantal-updates/universe chromium-codecs-ffmpeg-extra amd64 34.0.1847.116-0ubuntu~1.12.10.0~pkg900
  404  Not Found [IP: 91.189.92.200 80]
Err http://security.ubuntu.com/ubuntu/ quantal-security/universe chromium-codecs-ffmpeg-extra amd64 34.0.1847.116-0ubuntu~1.12.10.0~pkg900
  404  Not Found [IP: 91.189.91.13 80]
Err http://security.ubuntu.com/ubuntu/ quantal-security/universe chromium-browser amd64 34.0.1847.116-0ubuntu~1.12.10.0~pkg900
  404  Not Found [IP: 91.189.91.13 80]
Err http://security.ubuntu.com/ubuntu/ quantal-security/universe chromium-browser-l10n all 34.0.1847.116-0ubuntu~1.12.10.0~pkg900
  404  Not Found [IP: 91.189.91.13 80]
Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/c/chromium-browser/chromium-codecs-ffmpeg-extra_34.0.1847.116-0ubuntu~1.12.10.0~pkg900_amd64.deb  404  Not Found [IP: 91.189.91.13 80]
Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/c/chromium-browser/chromium-browser_34.0.1847.116-0ubuntu~1.12.10.0~pkg900_amd64.deb  404  Not Found [IP: 91.189.91.13 80]
Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/c/chromium-browser/chromium-browser-l10n_34.0.1847.116-0ubuntu~1.12.10.0~pkg900_all.deb  404  Not Found [IP: 91.189.91.13 80]
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages)
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages)
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main i386 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-i386_Packages)
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main i386 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?