We moved our VB6 application's database to another server and changed the connection string of our application to point to it. The following is the connection string and it does not work. It gives the error "[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied."
It seems our application has a problem with the named instance NEWMSSQL because when I try with just Data Source=10.10.10.10, it works, but that's not where the database resides so I can't use that. I thought the provider SQLOLEDB.1 is unable to recognize the named instance so I tried changing the provider to SQLNCLI.1, changed the connection string to the following and it works on my development machine.
What is an AD user? I'm using whatever user ID and password is entered by the user who happens to run the application. The user ID and password entered by the user is placed in the connection string to replace "uuuuuuu" and "ppppppp".
The new instance is a named instance - and it looks like you installed the new instance on the same node as an existing instance.
Verify that the SQL Browser service is up and running on that node - if not, it needs to be running to allow you access to the named instance. If you cannot start up this service, then you need to modify the named instance to use a static port - and then use that port in your connection string instead of the name.