I want to create a site only for register users, but I don't know how to make virtue mart only for register users.
http://www.charisiadis.gr/index.php/el/proionta/metaxeirismena
Virtue mart version 2.5
Do you mean you want only registered and logged in users to see the products & be able to buy? Or that all users see the products but only registered users can see the but botton/checkout?
These are all just configuration options, maybe with some template overrides to make the site look tidy. http://docs.virtuemart.net/
VirtueMart 2.5.x was a test/development series, not for use in a live store. Yoy should use the latest stable version, ie for the VM2 series that is 2.6.18
Look up for "content restriction pop up" module.