Sql DB Connection Error in Installed Apps on Client System

Question

Hello Guys,

 I have developed one windows application in .net framework 3.5, VS 2008  and inbuilt sql server Database,

But one issue  arise on client pc when I installed application, when I run the App then one Error coming relating to Database connection : 

'A network-related or instance-specific error occurred while establishing 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. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)'

 

My App config ConnectionString is : 

<add name="HMIS.Properties.Settings.Database1ConnectionString"

connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\DataBase\Database1.mdf;Integrated Security=True;User Instance=True"

providerName="System.Data.SqlClient" />

 

Also, I have installed Microsoft Sql Server Compact 3.5 SP1 on Client System 

 

Please me reply if U have solution

 

Thanks....