In SQL Server Configuration Manager, I have 2 SQL Servers :
SQLEXPRESS and MSSQLSERVER, how can I know which one is the default ?
I have more questions
I have created a new database called TEST with a new table called test1
In visual web developer I am adding new data connection , in the server name dropdown , after I refresh, only one server appears, why ?
And in the database name I have nothing.

You’ve got two instances of SQL Server running on your machine – you just specify which one you want to connect to in the server name box. The “default” will be the instance listed as MSSQLSERVER which you connect to by just specifying your machine name or “localhost” in the server name box.