about installing offline packages

Don't bother with aptoncd. Just copy the debs from /var/cache/apt/archives on the source system and copy them all to the same folder on the destination. You can now install the application offline.

If it doesn't work then cd to /var/cache/apt/archives and use the dpkg command to install the deb.

I just tried to copy my old bacup .deb files to /var/cache/apt/archives

But unable to paste

I logged in as admin but unable to change permissions for the archive folder

And

Can you give me an example how to use dpkg command?

What is the output of:

cat /etc/issue

On the destination?

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh# cat /etc/issue
Ubuntu 14.04 LTS \n \l

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh# cd /var/cache/apt/archives
root@mahesh-300E4Z-300E5Z-300E7Z:/var/cache/apt/archives# cat /etc/issue
Ubuntu 14.04 LTS \n \l

here is the output for your requested command

Then you can run :

sudo nautilus $HOME

You can then copy the debs. Your user does not have write access to the archives folder

Can I login as a root?
Is there any method to do that?

As when installing Ubuntu I created only one user

Thanks for the reply

I will check your suggested method

I just ran the command you provided

And a system program error just generated

I am giving output for your reuested command

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh# sudo nautilus $HOME

(nautilus:24731): Gtk-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

(nautilus:24731): GLib-GObject-WARNING **: invalid cast from 'GtkMessageDialog' to 'NautilusWindow'
**
ERROR:nautilus-window.c:2116:nautilus_window_get_slots: assertion failed: (NAUTILUS_IS_WINDOW (window))

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh#

Is there a bug in my system?

And how can I check my system is working fine?

I just upgraded nautilus

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh# sudo apt-get --download-only install nautilus
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  gnome-sushi
The following packages will be upgraded:
  nautilus
1 upgraded, 0 newly installed, 0 to remove and 359 not upgraded.
Need to get 485 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 http://in.archive.ubuntu.com/ubuntu/ trusty-updates/main nautilus i386 1:3.10.1-0ubuntu9.3 [485 kB]
Fetched 485 kB in 30s (16.1 kB/s)
Download complete and in download only mode

After running above same command following error is generated

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh# sudo nautilus $HOME

(nautilus:26011): Gtk-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files
Nautilus-Share-Message: Called "net usershare info" but it failed: 'net usershare' returned error 255: net usershare: cannot open usershare directory /var/lib/samba/usershares. Error No such file or directory

Please ask your system administrator to enable user sharing.

(nautilus:26011): GLib-GIO-WARNING **: Missing callback called fullpath = /root/.config/user-dirs.dirs

(nautilus:26011): GLib-CRITICAL **: Source ID 169 was not found when attempting to remove it

(nautilus:26011): GLib-CRITICAL **: Source ID 170 was not found when attempting to remove it

(nautilus:26011): GLib-CRITICAL **: Source ID 171 was not found when attempting to remove it

root@mahesh-300E4Z-300E5Z-300E7Z:/home/mahesh#

I guess that I dont have admin previleges

So as I asked previously

How to login as root OR the system admin?

Thanks Manfred Hampl, that solved my question.