title: C# Use One SQL Server database on multiple PC
body: <p>I made an application to insert and view data from service-based database (<code>cDatabase.MDF</code>).</p>
  <p>I have 3 PC, I want to run the application in all PC to insert the data in the same database</p>
  <p>I'm using SQL Server 2008 Express.</p>
  <p>Here are the steps I followed (I'm not sure if they are correct )</p>
  <ol>
  <li><p>open SQL Server Configuration Manager to turn on the TCP/IP from Client Protocol and Protocols for SQL Server Express</p>
  </li>
  <li><p>Set local Static IP for the PC. 192.168.1.10 , 192.168.1.20 , 192.168.1.30</p>
  </li>
  <li><p>Set the three PC on one WorkGroup</p>
  </li>
  <li><p>Turn off the firewall on all PCs</p>
  </li>
  <li><p>Change connection string to</p>
  <pre><code> Data Source=192.168.1.10\SQLEXPRESS;Initial Catalog=cDatabase;Integrated Security=True;User Instance=True;MultipleActiveResultSets=True
  </code></pre>
  </li>
  <li><p>I shared my application folder on the network from PC1 ( 192.168.1.10 )</p>
  </li>
  <li><p>when I open the applicaton from the shared folder (in all PCs) I get this error</p>
  <blockquote>
  <p>Login failed. The login is from an untrusted domain and cannot be used with Windows authentication.</p>
  </blockquote>
  </li>
  </ol>
  <p>How to fix this error? And thanks</p>