If it's and "error in connectivity", then try setting up a connection in VS with the Server Explorer pane:
1) Open Server Explorer.
2) Right click "Data connections" and select "Add connection"
3) In the dialog that follows, select your DataSource, and database, specify the security info, and press the "Test connection" button.
4) When the connection works, press "OK"
5) Highlight your database in the Server Explorer pane, and look at the Properties pane. A working example of the connection string will be shown, which you can copy and paste into your app or config file.
Then, don't do it like that! Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.
When you've done that, always list the fields you want to insert into in order - that way any DB changes don't break your code:
INSERT INTO myTable (myColumn1, myColumn2) VALUES (@C1, @C2)
And finally, perhaps if you opened the connect, and executed the query, the INSERT might work a bit better?
sc.Open();
cmd.ExecuteNonQuery();
would probably do it...