在終端執行以下命令（第一條是備份現有服務器列表，第二條是使用Gedit編輯，您也可以使用自己喜愛的編輯器編輯。）
sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup
sudo gedit /etc/apt/sources.list
從以下各服務器列表內容中選擇一段替換文件中的所有內容（請根據自己網絡環境設置更新服務器，以達到最快的速度。）
* Archive.ubuntu.com 更新服務器(歐洲)：
#
deb http://archive.ubuntu.com/ubuntu/ dapper main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ dapper-security main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ dapper-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ dapper-backports main restricted universe multiverse
deb http://archive.ubuntu.org.cn/ubuntu-cn/ dapper main restricted universe multiverse
* Ubuntu.cn99.com 更新服務器(江蘇省常州市電信，推薦電信用戶使用。）：
deb http://ubuntu.cn99.com/ubuntu/ dapper main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ dapper-updates main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ dapper-security main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ dapper-backports main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu-cn/ dapper main restricted universe multiverse
* Mirror.lupaworld.com 更新服務器(浙江省杭州市電信，亞洲地區官方更新服務器，推薦全國用戶使用。）：
deb http://cn.archive.ubuntu.com/ubuntu dapper main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu dapper-security main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu dapper-updates main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu dapper-backports main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/ubuntu-cn dapper main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu dapper-security main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu dapper main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu dapper-security main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu dapper-updates main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu dapper-backports main restricted universe multiverse
deb-src http://security.ubuntu.com/ubuntu dapper-security main restricted universe multiverse
* 上海市 上海交通大學 更新服務器（教育網，推薦校園網和網通用戶使用。）(目前已無法使用)：
deb http://ftp.sjtu.edu.cn/ubuntu/ dapper main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ dapper-backports main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ dapper-proposed main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ dapper-security main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ dapper-updates main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu-cn/ dapper main multiverse restricted universe
* 北京市清華大學 更新服務器（教育網，推薦校園網和網通用戶使用。)：
deb http://mirror9.net9.org/ubuntu/ dapper main multiverse restricted universe
deb http://mirror9.net9.org/ubuntu/ dapper-backports main multiverse restricted universe
deb http://mirror9.net9.org/ubuntu/ dapper-proposed main multiverse restricted universe
deb http://mirror9.net9.org/ubuntu/ dapper-security main multiverse restricted universe
deb http://mirror9.net9.org/ubuntu/ dapper-updates main multiverse restricted universe
deb http://mirror9.net9.org/ubuntu-cn/ dapper main multiverse restricted universe
* 中國 臺灣省臺灣大學 更新服務器（推薦網通用戶使用，電信PING平均響應速度41MS。）(強烈推薦,此源比較完整,較少出現同步問題)
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper-updates main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper-updates main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper-backports main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper-backports main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper-security main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ dapper-security main restricted universe multiverse
deb http://ftp.sjtu.edu.cn/ubuntu-cn/ dapper main multiverse restricted universe
* Mirror.vmmatrix.net 更新服務器（上海市電信，推薦電信網通用戶使用。）(目前已無法使用):
deb http://mirror.vmmatrix.net/ubuntu/ dapper main restricted universe multiverse
deb-src http://mirror.vmmatrix.net/ubuntu/ dapper main restricted universe multiverse
deb http://mirror.vmmatrix.net/ubuntu/ dapper-updates main restricted universe multiverse
deb-src http://mirror.vmmatrix.net/ubuntu/ dapper-updates main restricted universe multiverse
deb http://mirror.vmmatrix.net/ubuntu/ dapper-backports main restricted universe multiverse
deb-src http://mirror.vmmatrix.net/ubuntu/ dapper-backports main restricted universe multiverse
deb http://mirror.vmmatrix.net/ubuntu/ dapper-security main restricted universe multiverse
deb-src http://mirror.vmmatrix.net/ubuntu/ dapper-security main restricted universe multiverse
deb http://ftp.sjtu.edu.cn/ubuntu-cn/ dapper main multiverse restricted universe
ubuntu.cnsite.org 更新服務器 (福建省福州市 電信):
deb http://ubuntu.cnsite.org/ubuntu/ dapper main restricted universe multiverse
deb-src http://ubuntu.cnsite.org/ubuntu/ dapper main restricted universe multiverse
deb http://ubuntu.cnsite.org/ubuntu/ dapper-updates main restricted universe multiverse
deb-src http://ubuntu.cnsite.org/ubuntu/ dapper-updates main restricted universe multiverse
deb http://ubuntu.cnsite.org/ubuntu/ dapper-backports main restricted universe multiverse
deb-src http://ubuntu.cnsite.org/ubuntu/ dapper-backports main restricted universe multiverse
deb http://ubuntu.cnsite.org/ubuntu/ dapper-security main restricted universe multiverse
deb-src http://ubuntu.cnsite.org/ubuntu/ dapper-security main restricted universe multiverse
deb http://ubuntu.cnsite.org/ubuntu-cn/ dapper main multiverse restricted universe
*
到以下網址可以自定義產生若干源：http://www.ubuntulinux.nl/source-o-matic 以下網址有極其全面的源，以供補充：http://italy.copybase.ch/blog/lista-repository- sourceslist-ottimizzata-per-ubuntu-kubuntu-linux/
# 保存編輯好的文件，執行以下命令更新。
保存編輯好的文件，執行以下命令更新。
sudo apt-get update
sudo apt-get dist-upgrade