Setup could not connect to the database server - on Microsoft Dynamic AX 2009, Windows Server 2012 R2 and SQL Server 2008 R2

Hi,

I'm getting a connection-related issue between the SQL Server 2008 R2 database with Microsoft Dynamic AX 2009 running on the Windows Server 2012 R2 operating system, The problem I encountered was related to "Setup could not connect to the database server"

if anyone can explain why the Microsoft Dynamic AX installer can not connect to that database, 
please let me know what I should do.

Thank's