Bottom bar not showing at all.

Neither Ubuntu 10.04 nor 10.10 are supported in any way on the desktop (10.04 is still supported on the desktop)

I suggest you clean install Precise (Ubuntu 12.04) which is LTS and supported til April 2017. It also allows you to upgrade directly to Trusty directly, in April 2014.

There is no 'Linux 10'. It's not a thing.

Thanks for reply. First of all, I am sorry that I have little knowledge about computers( both software and hardware) in general. I believe, linux-10(that I have mentioned), is probably one of Ubuntu-10.04/10. I am using it for last three years. My computer was getting slower, so I was deleting many files and unistalling some programs as well. Thus I unistalled these programs by mistake.

Now, what do you mean by ''neither Ubuntu-10.04 nor .. is supported.. is still supported.''? And I would accept your suggestion of installing Ubuntu-12.04, but let me just ask again for once and all, is not there anything that can be installed (that I have uninstalled) to get back the 'menu bar' and bottom bar?

Bibek
I looked around in my four computers, for Ubuntu 10.04. The bottom bar has very little on it, everything is on top bar.I Googled Linux 10, it led to Linux Mint. Do you know how to use Terminal? If you don't,do this.
Open the Terminal (keyboard shortcut: Ctrl+Alt+T)

Enter the command lsb_release -a
Copy and paste what is after command. Copy and paste the results back here. Use site below for Ubuntu releases.

https://wiki.ubuntu.com/Releases

For Linux Mint releases and support check sites below.

http://www.linuxmint.com/oldreleases.php
http://forums.linuxmint.com/

Thanks Michael. Yes it is showing linux mint 10 (Julia). Now I am checking the sites, you have mentioned.

Then your OS is not supported here or in any of the Ubuntu support channels. It's support is entirely separate from Ubuntu's.