If you use a port other than the default (1433) to connect to your Microsoft SQL Server P6 EPPM database, you might have to perform additional configuration steps. To determine if you need to perform those steps, proceed as follows after installation of P6 Professional:
Launch P6 Professional from the client machine.
Choose Help, About Primavera P6 Professional.
From the About Primavera P6 Professional dialog box, click the System tab.
Under BRE Database, locate the database port number.
If the non-default port number appears, no further action is necessary.
If port number 1433 is listed, the user does not have Microsoft SQL Server 2005 Backward Compatibility Components installed. Proceed to the next step.
Choose to either globally specify the connection string in the P6 EPPM database SETTINGS table or install Microsoft SQL Server 2005 Backward Compatibility Components on each client machine.
Download an updated version of Microsoft SQL Server 2005 Backward Compatibility Components (SQL Server2005_BC.msi for 32-bit operating systems and SQLServer2005_BC_x64.msi for 64-bit operating systems) from the following location: http://www.microsoft.com/en-us/download/details.aspx?id=15748