Cannot connect to database master at SQL server at SERVERNAME\INSTANCE. The database might not exist, or the current user does not have permission to connect to it.

Hi

I have just built a new SQL Server, to which I want to create a new SharePoint 2010 Server. However, when I run the wizard using PSCONFIG, I get the following error;

Cannot connect to database master at SQL server at SERVERNAME\INSTANCE. The database might not exist, or the current user does not have permission to connect to it.

I have searched on the internet, however all posts point to checking port 1433 is enabled - which it is.

Turning the 'Windows Domain Firewall' off allows me to create the config databases, as does allowing incoming connections for the domain profile.

I want to keep the firewall on, but make the relevant exception. I cannot determine which one I need to add as a imcoming rule, any idea?