Windows Server 2008 R2 Network Load Balancing no balance

If you want a single session to balance across the two NLB nodes, you will need to change the Client Affinity to None. That will allow each request to be answered by the first available node. Be careful though, if you are using sessions this can cause issues where only one node is aware of the session.

In my experience, I haven't observed NLB to work in Round Robin fashion. To force a single load balancing with a low # of clients rapid refreshing took about 30 seconds before load balancing started.

That's not how NLB works. It does not load balance a single traffic stream across servers.

NLB load balances independent TCP or UDP sessions across the servers. So if you have two independent sessions then NLB should direct the first session to one server and the second session to the other server.