hi everyone, my question is how can I reset the whole program of ubuntu? what happened is that I dont know what I did but almost all of my icons disappeared........ and I wanna reset everything since the beggining. thank you for your help.....

Do you mean like do a re install?

yes kinda like that......

what should do I do?

Well, if you don't know what you did we certainly don't! Were you trying to make some changes? What were they? If you don't have any idea then a reinstall of the entire operating system would probably be the simplest. When you are doing something new it is always best to keep notes of the steps you are taking so you can go back and review/reverse them or have useful information to ask for help.

If this is a new install, why not just reinstall it the way you previously did, with the CD/DVD or whatever?
I've found that in most instances, you will get warning or error messages when you do something unexpected. Details are important when asking for help.

Just reviewing your post, you refer to Ubuntu as a program. Did you install it inside a windows partition with the wubi installer?

My vote goes for a fresh re install too. Unless you could tell us what changes you did that cause your desktop to misbehave.

Logout to the GUI login manager.
Ctrl+Alt+F1 and login as your usual self.
Ctrl+Alt+F7 and login. New, reset Desktop.

Next time, MAKE BACKUPS before you edit. Easiest "fix" ever.

and try to remember what you did last time, and do not repeat it!