For my simple app, I added a new setting named ITworldConn, changed the Type to (Connection String), and Scope to Application. To finish your new connection setting, click the small ellipsis button.

Interestingly, this connection string WILL successfully open an XLS file, which is just confounding to me, as from what I can tell an XLS file should use "Excel 8.0" to be successful.

We have our SQL server configured to only allow Windows accounts (i.e. not mixed). However, in some cases we are connecting from non-domain boxes and we want to specify a domain account to connect ...