Hi,

I think there might be something wrong with the alias you're creating. In the Add Network Library Configuration page check the following:

Server alias: This is the alias name to the server you're connecting to.

Network libraries: This should most likely be TCP/IP

Connection parameters: Either the network name or the IP-address of your SQL Server. If it's a named instance then it should be servername\instance

There is also option to un-check the "Dynamically determine port". If you're using this, trying un-checking and entering the port that is listening.

One other thing that comes to my mind is that it might be a name resolution problem. You're creating the alias using a name that was previously used by the old DB server. Do you have that entry in the HOST file? I believe it will first check that before doing any other name resolutions and it might mess up your configuration. You could also test this by creating the alias using a dummy name that doesn't exist in your network and see if it works.