Mutant: I dont think SQL Server has a problem with single " but does have a problem with single . Hes probably using Access?
Anyway to the problem..
You could do a String.Replace("\"", "\"\"") or as mutant suggested, replace it with like so; String.Replace("\"", ""). For SQL Server I usually just do a String.Replace("", "") (replace with two ). Theres also a SQL Server function which will take care of all of this for you, but unfortunately I cant remember what it is off of the top of my head.