刚装完debian，发现直接apt-get是用不了的，系统会提示你插入DVD，其实是源的配置问题，只需要在apt的源里面修改下配置就可以了。
打开apt源文件
sudo vi /etc/apt/sources.list
加入代码
deb http://http.us.debian.org/debian/ stable main
同时把deb cdrom:[Debian GNU/Linux 7.4.0 Wheezy - Official i386 DVD Binary-1 20 140208-12:26]/ wheezy contrib main注释掉
修改后的代码为
#
# deb cdrom:[Debian GNU/Linux 7.4.0 _Wheezy_ - Official i386 DVD Binary-1 20 140208-12:26]/ wheezy contrib main
# deb cdrom:[Debian GNU/Linux 7.4.0 _Wheezy_ - Official i386 DVD Binary-1 20 140208-12:26]/ wheezy contrib main
deb http://security.debian.org/ wheezy/updates main contrib
deb-src http://security.debian.org/ wheezy/updates main contrib
deb http://http.us.debian.org/debian/ stable main
# wheezy-updates, previously known as 'volatile'
# A network mirror was not selected during install. The following entries
# are provided as examples, but you should amend them as appropriate
# for your mirror of choice.
#
# deb http://ftp.debian.org/debian/ wheezy-updates main contrib
# deb-src http://ftp.debian.org/debian/ wheezy-updates main contrib
保存退出，执行更新命令
sudo apt-get update
更新完后就可以使用apt-get来安装软件了