with xhelp everyone can contact and ask for support,help and everything so i must uninstall contact module? i think no need for a contact module if i install xhelp.

that's a very good point - however, there is one catch. xhelp requires that the users trying to contact you have an account on your site. This will largely be eliminated in xhelp 0.7, which can create an account for the user at the same time they are trying to contact you. We are already considering alternative designs that move away from using the xoops_user table altogether to a system that uses the email address as the key, which would definitely make the contact module obsolete.