Ubuntu server: Please suggest me to get GUI interface...

The server doesn't have a GUI, it is a terminal based install. If you want a GUI OS, why did you not just install the desktop OS?

Does I can do everything in desktop OS what I am doing in serever...?

Does I can do everything in desktop OS what I am doing in serever...?

Yes, you just get the desktop by default on the desktop OS. Why did you install the server OS?? If you want an SQL server etc, you can install that on the desktop OS with no detrement (except you will be running the X server which reduces security, elongates boot time and uses more resources), but you are clearly new to the OS and were going to install the dekstop anyway.

Makes no sense at all....

Is it?

See, I needs to configure Email server, Web server, DNS server.

Does all these features are available in Ubuntu desktop OS...? Then why Ubuntu server OS is being specifically!

Please assist me...

Then install those frm software centre and it wil run as a service as you expect. The spackage sources are no different in the desktop OS to the server install, so you can install what you want. If you MUST install a GUI on the server then run:

sudo apt-get install lxde

and use that, its a much lighter desktop but in future I suggest you install a desktop OS

yeah super! Thank you.....

Please provide the link for Ubuntu software center.............

It is in the desktop OS. Or you can install it with:

sudo apt-get install softare-center-gtk

This commmand is not working. Its showing invalid command.

And another onething the commands "aut" and "iface" is not working Ubuntu server 12.04 LTS.....why?

aut isn't a command, neither is iface, where are you getting this from?

Oops its "auto" not "aut"..

I got this from Ubuntu documentation.

And "sudo apt-get install softare-center-gtk" this is not working..

Are you trying to configure the network by any chance, those are words that go in /etc/network/interfaces file....

Yes, I was trying to configuring the network.

Then those are not commands, they are settings for the file I gave earlier. Your LAN should give DHCP so you can get network access, if you want a CLI GUI, you can install wicd and use that. It is a decent ncurses UI to network config.