When installed SMS admin console on Windows 7 it would not expand the Query tree so I couldn't remote control any machine (The same problem can affect Windows Vista)

It turns out the problem is the Windows Firewall blocks the inbound WMI connections, so you could either turn off the firewall or create rules that allow the connection

Go to Start and type Windows Firewall and select the firewall then seelct Advanced Settings. This will open the Firewall application.

Select Inbound Rules and find the Windows Management Instrumentation rules and enable each one.

SMS Admin console should work ok now