vScope connects to the SQL Server Browser Service during discovery. In SQL Express, the SQL Server Browser Service is not active by default, and it therefore needs to be started.
- Activate TCP/IP for SQL Express. Follow step 1 in this guide:
Microsoft Blog – Discovery of SQL express instances running on dynamic ports - Ensure that SQL Server Express is listening to the public IP number
- Ensure that the SQL Server Browser Service is running:
Microsoft Technet: How to: Start and Stop the SQL Server Browser Service (SQL Server Express) - Make sure port 1434 (SQL Browser Service) is open in the firewall
- Make sure that the dynamic port that the SQL instance is listening to is open in the firewall:
Splandme.com: SQL server finding TCP port number SQL instance is listening on