connection string using windows auhtentication .net

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>
  <connectionStrings>
    <add name="TESTDBConnection" connectionString="Server=.\SQLEXPRESS2;Database=TESTDB;Trusted_Connection=Yes;"/>
  </connectionStrings>
</configuration>