Hi i have DSL connection and i want 2 it conected with LAN in our LAN there is 40 users and i want internet connection only 25 user how its possible just suggested me wait for your response thanx

The easiest way is to configure your clients IP-addresses manually and enter the gateway on just the 25 that are supposed to be able to connect to the internet. Otherwise you could set up RRAS on your server, but for 25 users it's a little over the top.