Hi,

When i log into the linux system, I am going to ordinary user mode. What is the command to change my mode to administrator mode. I am the administrator as well. I know the password of Admin too. Please help me.

From a terminal do
then digit the admin (root) password when prompted. The "-" stats for "inherit the root's environment upon switching to root user". An advice: never login as root in the X system (that is from the graphical login) otherwise you will open some holes in the security wall of your system.

Thanks boss

On some distro's, you can select an administrative program in the menu (such as SuSE's yast) and you will be prompted for a password.

Using sudo for each command may be better than using "su -". If you use Ubuntu, the root account is disabled and "su -" won't work anyway.

Please put your distribution in your user profile. That can solicit more distro specific responses instead of generic ones.
For example, if it is SuSE, someone can advise you on which YaST2 module to use. Or to use an rc<service> script instead of the service command. Distro's vary in how services are started with either "System V" style or BSD style. Knowing your distro can prevent getting advice for a different distro.

Hi, if you are referring to it as Administrator mode, you might want to be very very careful with root, it can be very dangerous to the machine as you can easily run a command like "rm -rf /" that will almost certainly break a linux system if it doesn't warn/stop you (similar to format C: in windows/DOS).

I would bet their is a back door somewhere, excluding single user mode... something probably like "sudo /bin/sh"... but I dunno, I don't use ubuntu (their anti CLI ways gives me the creeps =/) but I'd probably figure out a way if I had to use it.

Thanks all of you but I need to do my homework. So it requires me to be in administrator mode.
1) I have to find all of setuid files using find command
2) is using sudo command something.....

You can enable the root (admin) account in Ubuntu:

sudo passwd root

You will still be asked for your regular user password when opening various utilities from the GUI.

Thank you All.

Thank you all of you my friends.