Not able to connect C# exe with SQL Server

I have to deploy this stand-alone file in different client machine.

 

Consider, i have two machine - Machine A and B.

 

in Machine A, i have installed SQL Server 2008 R2 and VS2013 for development.

 

Connection string i have used for development:  "Data Source=AssetName\SQLEXPRESS;Initial Catalog=Test_Database;Integrated Security=True" which is working fine in Machine A. when i tried same on Machine B it is not connecting to the Sql Server on Machine A.

 

When i searched on internet, i got many references suggesting to use Service-Based Database in VS. however i am finding difficult to understand how service-based database is working. i couldn't see any connectivity between the server and service-based database. can anyone help me to on this..

 

Also please let me know to connect the SQL Server on Machine A do i need to SQL Server Management Studio on Machine B??? 

 

 

 Error msg:

System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while extablishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.