How to change ubuntu 7.10 into xubuntu
 

hello how can i change my linnux distro ubuntu 7.10 into xubuntu.

By installing the other version?

Normally, it would be

sudo apt-get install xubuntu-desktop

but 7.10 is unsupported, updates and packages are not available anymore, you will have to upgrade to 8.04 or 9.10 (current) to be able to install anything (without spending too much time)

Download the new ISO and do a full install.. (Use the 'Use entire disk') option. It will delete anything else that was on the existing drive.

.. Backup anything on it first tho!

^^ It will not work with 7.10, you still have to upgrade to use this "solution"

^^You are right.7.10 has to be updated first.

Ok thanks. In this solution, can my laptop get more faster because i install xubuntu?

I would recommend backup any work/files you want to keep and do a fresh install. If you partition your disk like this

/root
/usr
/home

Next time you do any upgrades you can upgrade your root system and should be able to keep your files.

I don't see the need for a separate /usr, but for a swap partition.

Well partition is more of a matter of preference these days. Some people say you should do a serperate /var to keep your root from filling up with logs. But typical yea

/root
/home

is a good way

If you only want to speed up your laptop then changing from Gnome and gdm to Xfce and xdm may be enough. xubuntu is a "complete desktop" including abiword (word processor) and transmission (bittorrent client). OTOH, 7.10 is a bit long in the tooth so this might be a good opportunity to upgrade and do a clean install as already suggested. ubuntu is a fairly heavy distro, though; if you laptop isn't very powerful then a lighter distro might better suit your needs.