Synaptic Pakage Manager wiull not open

Reboot with a "recovery mode" kernel and type the following in terminal

 "chown root /etc/sudoers"

 Rajkumar.R

Thanks for you suggestiom, no progress. Got 'no such comman', 'no such file'.

If it is not too much trouble I would appreciate an answers that explains if possible the problem and how an answer might solve it. I want to learn about Linux, not just solve problems by rote.

In Linux, the administrator account is called root. The Ubuntu Security Model has root disabled by default. Instead a group of users with extended rights can assume root rights for a period of time using sudo/gksudo/gksu/kdesu (see https://help.ubuntu.com/community/RootSudo).

The file '/etc/sudoers' lists all users with superuser rights, i.e. those than can use the 'sudo' command.

Currently, the user with the ID 1002 owns this file, while it should be owned by root. Updates generally don't change permissions, so you must have somehow altered this yourself.

Anyhow, it's gotta be changed back for your system to function properly. The problem lies in the fact, that you have to have superuser rights to change permissions, which you can't assume, since sudoers is screwed.

This vicious cycle can be broken by booting into Recovery Mode (usually the second option in the GRUB menu). Recovery Mode is essentially a command line interface with the root account enabled. If the GRUB menu does not show during startup, hit 'ESC' when you see 'GRUB loading - Stage 1.5' appear on your screen.

In Recovery Mode, drop to a root shell, type 'chown root /etc/sudoers' and hit the Enter key.

The chown command changes a target file's ownership. It's syntax is 'chown [-option] username /path/to/file'.

Boot back into your regular Ubuntu install, log in with your regular username and pass, Synaptic should open from the GUI.

As an aside, you should never run 'sudo synaptic', Synaptic being a graphical application, it should be run with 'gksu synaptic' (see above link).