[Linux Debian 8]: Driver Installation asks me to insert a disc

Question

So I recently installed Debian 8 and am currently trying to get the software configured with my NVIDIA video card. The official Debian page instructed me to do this:

1. Add

   deb http://http.debian.net/debian/ jessie main contrib non-free
   

   to the /etc/apt/sources.list.

2. Run

   # aptitude update
   

   and then run

   # aptitude -r install linux-headers-$(uname -r|sed 's,[^-]*-[^-]*-,,') nvidia-kernel-dkms
   

I am not sure what I did wrong, because when I run the second command, it displays this message to me:

0 packages upgraded, 16 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/21.9 MB of archives. After unpacking 80.5 MB will be used. Do you want to continue? [Y/n/?] y Media change: Please insert the disc labeled 'Debian GNU/Linux 8.1.0 _Jessie _ - Official amd64 kde-CD Binary-1 20150606-14:19' into the drive '/media/cdrom/' and press [Enter].1

I do not possess an optical drive so this creates a great issue for me.

I got the instructions from here.  See “Installation: Debian 8 'Jessie'”

Solution

There is probably a line in /etc/apt/sources.list (or in one of the files in /etc/apt/sources.lists.d/) starting with

deb cdrom ...

Comment this line out and Debian won’t try to install packages from this disc.