When you have problems connecting to the Sql Server database then open the SQL Server Configuration Manager and verify if:
- SQL Browser service is running
- TCP/IP is enabled
These screenshots are from MS SQL Server 2008 R2 Express, but other versions should look similar.
The first thing that can block a connection to SQL Server is a firewall. If you have any firewalls, make sure they are configured to allow connections to SQL Server.
Please check your Firewall Settings
Use a different database
Call Setuptv.exe with --configure-db to make it ask for database details. Then just give a different database name and setuptv.exe will create a new database for you or use the old one depending on your usage.