You need to Enable a network protocol to allow connectiosn to the SQL Server. Here's an article on how to do it, http://msdn.microsoft.com/en-us/library/ms191294.aspx. If that doesn't work you also have to allow traffic through windows firewall to that address and port, here's an article on how to do that, http://technet.microsoft.com/en-us/library/ms175043(v=sql.120).aspx