title: .NET MSI Install project - Overwrite previous version
body: <p>I have an MSI installer project that installs a windows service.</p>
  <p>My version numbering method is best described by this post: <a href="https://stackoverflow.com/questions/64602/what-are-differences-between-assemblyversion-assemblyfileversion-and-assemblyin">What are differences between AssemblyVersion, AssemblyFileVersion and AssemblyInformationalVersion?</a></p>
  <p>I am not changing the Version of my install project as that is not changing, and I've had too many issues when doing that.</p>
  <p>I have already installed my service with the following assembly versions</p>
  <pre><code>[assembly: AssemblyVersion(&quot;4.3&quot;)]
  [assembly: AssemblyFileVersion(&quot;4.3.0.0&quot;)]
  </code></pre>
  <p>I just built an MSI installer to this version:</p>
  <pre><code>[assembly: AssemblyVersion(&quot;4.3&quot;)]
  [assembly: AssemblyFileVersion(&quot;4.3.1.0&quot;)]
  </code></pre>
  <p>When I run the MSI it tells me that I need to uninstall the previous version.</p>
  <p>How do I get around this? What I ultimately would like to do is:</p>
  <ol>
  <li>Install an MSI</li>
  <li>Install (re: upgrade to) another version that overwrites the previous version (prompt or no prompt)
  a. I do not want to have to un-install before I install an update.</li>
  </ol>
  <p>My installer project properties are:</p>
  <blockquote>
  <p>RemovePreviousVersions - True</p>
  <p>InstallAllUsers - True</p>
  <p>DetectNewerInstalledVersion - False</p>
  <p>Version - 4.3.0</p>
  </blockquote>
  <p>What I have tried:</p>
  <ul>
  <li>Update the Assembly Version of the project. However, this creates multiple versions of the same products in Add Remove Programs. Not want I want for windows services</li>
  <li>Change the version # on the installer project. But this creates a lot of errors when trying to install any version of the MSI. I even got warnings that I was installing on a network drive! (wow).</li>
  </ul>
  <p>Any help would be rockin!</p>
  <p>Thanks.</p>