KISS (Keep it stupid simple) 🙂
“System.Data.OleDb.OleDbException: [DBNETLIB][ConnectionOpen (PreLoginHandshake()).]General network error. Check your network documentation.” – that was the wife having an issue.
I told her: okay, do you have SQLNCLI? Obviously, she had it installed.
Me: well then, check here:
http://blogs.msdn.com/sql_protocols/archive/2005/10/22/483684.aspx
http://blogs.msdn.com/sql_protocols/archive/2005/10/29/486861.aspx
It turned out that SQL Browser service was not started. Again, KISS or be KISS-ed.
Simple lesson learned
SQL-PLAY 