初めまして。
過去に類似した質問が多数あるような基本的な質問で、申し訳ありません。ご教授お願いします。

■ubuntuのバージョン
14.04

■質問内容
「sudo apt-get update」を実行したところ、以下のエラーメッセージが発生しました。
対処方法をご教示ください。
※old-releases.ubuntu.comに変換する作業（trusty-securityを除く）は実施済み
【メッセージ】
Hit http://security.ubuntu.com trusty-security InRelease
Ign http://old-releases.ubuntu.com trusty InRelease
Hit http://security.ubuntu.com trusty-security/main Sources
Ign http://old-releases.ubuntu.com trusty-updates InRelease
Hit http://security.ubuntu.com trusty-security/universe Sources
Ign http://old-releases.ubuntu.com trusty-backports InRelease
Hit http://security.ubuntu.com trusty-security/main amd64 Packages
Ign http://old-releases.ubuntu.com trusty Release.gpg
Hit http://security.ubuntu.com trusty-security/universe amd64 Packages
Hit http://security.ubuntu.com trusty-security/main Translation-en
Ign http://old-releases.ubuntu.com trusty-updates Release.gpg
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Ign http://old-releases.ubuntu.com trusty-backports Release.gpg
Ign http://old-releases.ubuntu.com trusty Release
Ign http://old-releases.ubuntu.com trusty-updates Release
Ign http://old-releases.ubuntu.com trusty-backports Release
Err http://old-releases.ubuntu.com trusty/main Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty/restricted Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty/universe Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty/multiverse Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty/main amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty/restricted amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty/universe amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty/multiverse amd64 Packages
  404  Not Found
Ign http://old-releases.ubuntu.com trusty/main Translation-en_US
Ign http://old-releases.ubuntu.com trusty/main Translation-en
Ign http://old-releases.ubuntu.com trusty/multiverse Translation-en_US
Ign http://old-releases.ubuntu.com trusty/multiverse Translation-en
Ign http://old-releases.ubuntu.com trusty/restricted Translation-en_US
Ign http://old-releases.ubuntu.com trusty/restricted Translation-en
Ign http://old-releases.ubuntu.com trusty/universe Translation-en_US
Ign http://old-releases.ubuntu.com trusty/universe Translation-en
Err http://old-releases.ubuntu.com trusty-updates/main Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/restricted Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/universe Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/multiverse Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/main amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/restricted amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/universe amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty-updates/multiverse amd64 Packages
  404  Not Found
Ign http://old-releases.ubuntu.com trusty-updates/main Translation-en_US
Ign http://old-releases.ubuntu.com trusty-updates/main Translation-en
Ign http://old-releases.ubuntu.com trusty-updates/multiverse Translation-en_US
Ign http://old-releases.ubuntu.com trusty-updates/multiverse Translation-en
Ign http://old-releases.ubuntu.com trusty-updates/restricted Translation-en_US
Ign http://old-releases.ubuntu.com trusty-updates/restricted Translation-en
Ign http://old-releases.ubuntu.com trusty-updates/universe Translation-en_US
Ign http://old-releases.ubuntu.com trusty-updates/universe Translation-en
Err http://old-releases.ubuntu.com trusty-backports/main Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/restricted Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/universe Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/multiverse Sources
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/main amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/restricted amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/universe amd64 Packages
  404  Not Found
Err http://old-releases.ubuntu.com trusty-backports/multiverse amd64 Packages
  404  Not Found
Ign http://old-releases.ubuntu.com trusty-backports/main Translation-en_US
Ign http://old-releases.ubuntu.com trusty-backports/main Translation-en
Ign http://old-releases.ubuntu.com trusty-backports/multiverse Translation-en_US
Ign http://old-releases.ubuntu.com trusty-backports/multiverse Translation-en
Ign http://old-releases.ubuntu.com trusty-backports/restricted Translation-en_US
Ign http://old-releases.ubuntu.com trusty-backports/restricted Translation-en
Ign http://old-releases.ubuntu.com trusty-backports/universe Translation-en_US
Ign http://old-releases.ubuntu.com trusty-backports/universe Translation-en
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/main/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/restricted/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/universe/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/multiverse/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/restricted/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/universe/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty/multiverse/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/main/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/restricted/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/universe/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/multiverse/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/restricted/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/universe/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-updates/multiverse/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/main/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/restricted/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/universe/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/multiverse/source/Sources  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/restricted/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/universe/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/trusty-backports/multiverse/binary-amd64/Packages  404  Not Found


■sources.listの内容（コメントアウト部分は省略）
deb http://old-releases.ubuntu.com/ubuntu trusty main restricted
deb-src http://old-releases.ubuntu.com/ubuntu trusty main restricted

deb http://old-releases.ubuntu.com/ubuntu trusty-updates main restricted
deb-src http://old-releases.ubuntu.com/ubuntu trusty-updates main restricted

deb http://old-releases.ubuntu.com/ubuntu trusty universe
deb-src http://old-releases.ubuntu.com/ubuntu trusty universe
deb http://old-releases.ubuntu.com/ubuntu trusty-updates universe
deb-src http://old-releases.ubuntu.com/ubuntu trusty-updates universe

deb http://old-releases.ubuntu.com/ubuntu trusty multiverse
deb-src http://old-releases.ubuntu.com/ubuntu trusty multiverse
deb http://old-releases.ubuntu.com/ubuntu trusty-updates multiverse
deb-src http://old-releases.ubuntu.com/ubuntu trusty-updates multiverse

deb http://old-releases.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu trusty-security main
deb-src http://security.ubuntu.com/ubuntu trusty-security main
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe


以上です。どうぞ宜しくお願い致します。