i just opened the comp then went to tools to show hidden files, but....
ididn,t find the folder options neither in TOOLS nor Control Panel.
What should i do?

Why do you want to show hidden files, your folder options should not be hidden.

Start > Windows Explorer > Tools > Folder Options

Add folder options to the control panel, right click start button, scroll down to properties, Click on properties, click on tab customize, click advanced tab, put a check mark "Display as a Menu"

If you just want to add control panel to start menu, put a check mark "Display as a Link" and the control panel should be in your start menu.

You can run this reg fix from Kellys Korner, line 129. http://www.kellys-korner-xp.com/xp_tweaks.htm
Download it and then choose run. Agree to change the registry and it will place the option back for you.
Always have a backup of the registry before changing anything.