i do not know how to uninstall 3 of 5 kernels OS on my computer

What OSes do you have installed? Do you mean you want to remove unnecessary kernels?

First of all I installed Windows7, them Ubuntu 12.04 along side, and both of them I wanna save without any changes. Another OSes Kubuntu 12.04 I wanna delete.

This is a two step process

1. Edit grub so only Ubuntu and Windows 7 are there. See here:
https://help.ubuntu.com/community/Grub2

2. Delete the unused partitions to free up the space.
In Ubuntu you can use GParted for this. There are tools under windows too.

Yes, I wanna remove kernels. I tried to delete some partitions but then I had problems with GRUB. That's why I installed 2 more OSes.

I've got Gparted but i don't know which partition belongs to.

Well , some people writing programs to make our lives better and easier.

This program is one of them => https://help.ubuntu.com/community/OS-Uninstaller

Use it to uninstall any OS you don't want.

Thanks

Great thanks to everyone who gave right answer i ever could imaging. Thank you Thank you Thank you

Yes , good
but please mark the answer you used , as the correct answer , for future-help-others with same question. (You can re-edit your question).

Thanks

I haven't solved my problem yet. But I'm sure I'll do with those links I've got here. I let you know witch one helped

Can you give the output of:

sudo update-grub; lsb_release -a; uname -a

Thanks

I'll give this information later.

By the way, i can't download the OS-uninstaller. This program is available only in Ubuntu distribution but it's too expensive for me to download it. Where can i find This programm apart?

Expensive ? I don't know what you mean with word "expensive" , because the program is FREE !

Did you follow the instructions on site ? https://help.ubuntu.com/community/OS-Uninstaller#A2nd_option_:_install_OS-Uninstaller_in_Ubuntu
You have to boot from a Live - USB / CD of Ubuntu and run 2 commands in terminal.

Thats it.
End . Done . Ready. :-)

It's a matter of 5-10 minutes top.

What OSes do you have installed exactly?

Expensive means i have to pay for every mb. Internet is not for free in my country.
There is 5 OSes on my comp, Windows7, Ubuntu 12.04, Kubuntu 12.04 in English, Kubuntu 12.04 in Russian and one more Ubuntu 12.04.

Why did you install them separately!? The only difference is a different default desktop. You can install all te desktops on ONE of the OSes and select the desktop at login. Otherwise there is zero difference in the releases.

I understand that Ubuntu Secure Remix can solve my problem in one click, but to download 790 mb is too expensive for me at this moment. That's why i asked for OS-uninstaller only.

Why separately? Because I'm learning and i don't know a lot of things in comp world.

@igo

Ok, I understand about "expensive" if you pay per MB. But you don't have to download something. And what is this Ubuntu secure remix ? I did't tell you to download any distribution .

Don't you have a bootable Linux USB/CD/DVD , something ? Just boot from this Live CD/DVD/USB (anything you have) and click "Try Ubuntu" (means , not install the distro just try it) , then open a terminal (CTRL+ALT+T) and apply below commands:

sudo add-apt-repository ppa:yannubuntu/os-uninstaller
sudo apt-get update; sudo apt-get install -y os-uninstaller && os-uninstaller

you will see the window opens , and CAREFULLY select what OS you want to uninstall. Thats it.
The application "OS-UNINSTALLER" is some.. KBs.

Thanks

Ok, I'll try that way.

Bingo. i did it. Sorry, we did. It was easy.

[r] NikTh [/r] Thank you very much

This has solved my problem "sudo add-apt-repository ppa:yannubuntu/os-uninstaller
sudo apt-get update; sudo apt-get install -y os-uninstaller && os-uninstaller"