how to open password protected excel file in .net

Question

 error : External table is not in the expected format.

 

code:

 

connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;" + @"Data Source=" + fName + ";" + @"Jet OLEDB:Database Password=Test" + ";" + @"Extended Properties=" + Convert.ToChar(34).ToString() + @"Excel 8.0" + Convert.ToChar(34).ToString() + ";";

 

OleDbConnection OleDbcon = new OleDbConnection(connectionString);
OleDbDataAdapter adp = new OleDbDataAdapter("select * from [Sheet1$]", OleDbcon);

 
adp.FillSchema(dt1, SchemaType.Source);
adp.Fill(dt1);