The usual error as shown below - “[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied.” - appears when creating a visual basic program with SQL database application which has an incorrect connection set-up (especially computer with firewall) and an improper connection string.
Connection string used for LAN connection:
“Provider=MSDATASHAPE; Data Provider=SQLOLEDB.1; Data Source=YourComputerName\YourDatabaseInstanceName; Initial Catalog=YourDatabaseName; User ID=sa; Password=YourPassword; Integrated Security=SSPI; Persist Security Info=False;”
Connection string using a DSN (Highly recommended one, it will work in a Windows Network Environment):
“Provider=MSDATASHAPE; DSN=YourDSNname; UID=sa; PWD=YourDatabasePassword;”
Tip - Create a DSN Connection using the Data Sources (ODBC) Application which can be found under the Administrative Tools at the Control Panel section. Must use the SQL Server Instance Name (ex. YourServerName\YourInstanceName) and Named Pipe (ex. \\YourServerName\pipe\MSSQL$YourInstanceName\sql\query).
Note: YourServerName is the computer name of the server