We are trying to install SQL Server 2008 standard onto our server that is
also running SharePoint 3.0 services. Before doing the install, as per
http://msdn.microsoft.com/en-us/library/ms175043.aspx, we added TCP port
1433 on the Windows Firewall Exception tab. However, the install fails at the
"running post-Windows Installer configuration timing actions" >
RS_RunInstallScriptsAction_Cpu64 step due to error:

"A network-related or instance-specific error occurred while establishing a
connection to SQL Server. The server was not found or was not accessible.
Verify that the instance name is correct and that SQL Server is configured to
allow remote connections. (provider: TCP Provider, error: 0 - No connection
could be made because the target machine actively refused it.)"

On the server, when we run "telnet localhost 1433" it returns:
"Could not open connection to the host, on port 1433: Connect failed"
which I believe explains why the install is failing.

We are wondering if it is possible that a setting from the sharepoint
services (i.e., Windows Internal Database) install is interfering. We believe
that the Windows Internal database for SharePoint does not allow remote
connections. We speculate that there could be a registry setting that is
carrying over from the Sharepoint install to cause this.