Media changed: please insert the disk labeled 'Debian GNU/Linux 7.4.0 _Wheezy_

["Theodore Alcapotaxis" <theotaxis@mail.com>]

I installed Debian 7 using a USB flash drive "burned" from the first DVD ISO of the Debian installation CD/DVD.

I did a very minimal install without Debian desktop environment, Print server and Standard system utilities.

After installation and a reboot, I was presented with a console with the words Debian GNU/Linux 7 hostname tty1. I supplied the login username and password.

After I typed the command sudo apt-get install xorg, an error message popped up stating:

Media changed: please insert the disk labeled 'Debian GNU/Linux 7.4.0 _Wheezy_ - Official amd64 DVD Binary-1 20140208-13:47' in the drive and press Enter

I inserted the same USB flash drive into the same slot and after waiting for a few seconds, I pressed Enter.

The same error message popped up.

I have tried the following steps on the advice of some of my colleagues:

1. remove/delete all the entries in /etc/apt/sources.list and reboot the computer
2. dmesg shows that the USB thumb drive is mounted on /dev/sdb1
3. sudo mount /dev/sdb1 /media/usb0
4. sudo apt-cdrom -m -d /media/usb0 add

After doing the above, the following error message appears:

[quote]

Using CD-ROM mount point /media/cdrom/
Identifying.......{a long string of alphanumeric characters}
Scanning disc for index files...............
Found 0 package indexes, 0 source indexes, 0 translation indexes and 0 signatures
W: Failed to mount '/dev/sr0' to '/media/cdrom/'
E: Unable to locate any package files, perhaps this is not a Debian disc or the wrong architecture

[end quote]

I prefer to install Xorg (60MB) and gnome-core (400MB) from the DVD disc. The NGO that I am working with is in a developing country with a very basic internet access infrastructure. Internet access is very patchy and the average download speed is less than 2 Mbps.

A solution will be much appreciated.

Regards.

Theodore