title: ERROR Login failed for user '<User>'. after publishing the web
body: <p>I am getting an error after publishing a web. it say "Login failed for user ''. it works fine for the process that is not connecting to database, but when executing a process that need to connect to database the error showed up. 
  here is the error:</p>
  
  <blockquote>
    <p>System.Data.SqlClient.SqlException: Login failed for user ''</p>
  </blockquote>
  
  <p>I already tried some suggestion from internet to solve it, but it still the same. here my web.config:</p>
  
  <pre><code>&lt;connectionStrings&gt;
   &lt;add name="ConnectionString" providerName="System.Data.SqlClient" connectionString="Data Source=&lt;Name of the server&gt;;Initial Catalog=Booth_db;Integrated Security=True /&gt;
  </code></pre>
  
  <p></p>
  
  <pre><code>&lt;system.web&gt;
    &lt;compilation debug="true" strict="false" explicit="true" targetFramework="4.5" /&gt;
    &lt;httpRuntime targetFramework="4.5"  /&gt;
    &lt;customErrors mode="Off"/&gt;
    &lt;globalization culture="en-GB"/&gt;
  &lt;/system.web&gt;
  </code></pre>
  
  <p></p>
  
  <p>I also tried adding impersonate identity but it give me an error on that impersonate identity.
  do you have any experience about this problem? </p>
  
  <p>Thanks in advances.</p>