i wrote a CD with an iso-image from debian.org. the debian-7.5.0-amd64-CD-1.iso from this folder. Debian Wheezy 7.5 stable 64bit There was an error at Select and install software step. It said Retrieving file 770 from 800 and then it failed the installation. I continued the instal and when i opened the computer it doesn't work the Ctrl + Alt + F7 as i waited. It starts at tty1 and after logging in i edited config file cause it had a lot of errors and said E: Unable to correct problems, you have held broken packages or Couldn't found the package. FILE: /etc/apt/sources.list # deb cdrom:[Debian GNU/Linux 7.5.0 _Wheezy_ - Official amd64 CD Binary-1 20140426-13:37]/ wheezy main #deb cdrom:[Debian GNU/Linux 7.5.0 _Wheezy_ - Official amd64 CD Binary-1 20140426-13:37]/ wheezy main deb http://security.debian.org/ wheezy/updates main contrib non-free deb-src http://security.debian.org/ wheezy/updates main contrib non-free deb http://ftp.us.debian.org/debian/ squeeze main contrib non-free deb-src http://ftp.us.debian.org/debian/ squeeze main contrib non-free After that i tried to install xfce4 as desktop environment. Guide found at Linux Panda But it print at terminal: What i sould do? How i can fix this problem?