1、更新/etc/apt/source.list文件
deb http://old-releases.ubuntu.com/ubuntu/ natty main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-security main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-updates main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-proposed main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-security main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-updates main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-proposed main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse
2、sudo apt-get update
3、更新系统
3.2 确保update设置勾选全部
todo 图
3.1 Alt + F2 输入update-manager
按提示升级即可。
Ubuntu12.04_X64 apt-get install报错404：http://www.linuxdiyf.com/linux/14328.html
ubuntu不能使用apt-get命令，404 Not Found：http://www.linuxdiyf.com/linux/13949.html
Ubuntu Kylin 15.04下的PPA源会报404，执行apt-get update卡死：http://www.linuxdiyf.com/linux/12047.html
apt-get update更新源列表出现404 Not Found错误：http://www.linuxdiyf.com/linux/9969.html
解决Ubuntu运行命令‘APT-GET UPDATE‘时‘404 NOT FOUND’错误：http://www.linuxdiyf.com/linux/6528.html