When you enable RDP for Windows 7 (default is enabled) , you will also need to add a firewall rule to accept RDP connections. By default this is not enabled. You can easily do it via the Windows firewall MMC by running the following command
or Add a rule for the same via the command prompt. Add a rule for accepting incoming RDP connections on TCP 3389.
netsh advfirewall firewall add rule name="RDP Allow TCP" dir=in protocol=tcp localport=3389 action=allow