Fresh installed windows server 2008 r2 and added roles AD DS. There is one group with 5 users. while i used to login with a certain user from remote machine which is in the same domain, the login failed and the msg appears similar as no login instance in the server.
When you have an AD problem, you usually have a DNS problem. Chances are the client is using the wrong DNS server, or the DC isn't using itself/other DCs as DNS servers.
Double check DNS settings on both ends. If everything looks fine, then you probably missed the problem.