title: Install Visual Studio 2015 express on Windows 7
body: <p>I have read <a href="https://stackoverflow.com/questions/32450972/cannot-install-visual-studio-2015-community-on-windows-7">this</a>, <a href="https://stackoverflow.com/questions/31346692/microsoft-visual-studio-setup-blocked">this</a>, <a href="https://stackoverflow.com/questions/31588676/visual-studio-2015-setup-blocked">this</a>, <a href="https://stackoverflow.com/questions/32372725/microsoft-visual-studio-professional-2015-setup-blocked">this</a> and <a href="https://stackoverflow.com/questions/32003203/install-visual-studio-2015-community-edition-on-windows-7">this</a> questions and answers, none of them have help me at all.</p>
  
  <p>I'm trying to install Visual Studio 2015 Express or Community edition, I have W7 SP1, I have tried with admin rights, I've checked that no preview VS have been installed but no matter what I do, I still can't install VS and I don't understand what the log says, I'll append a picture and what I think is an important part of the log file:</p>
  
  <p><a href="https://i.stack.imgur.com/H74i7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/H74i7.jpg" alt="enter image description here"></a></p>
  
  <pre class="lang-bash prettyprint-override"><code>[0D48:1794][2015-10-20T19:36:45]i000: MUX:  Feed uri to register: http://go.microsoft.com/fwlink/?LinkID=558779&amp;clcid=0x409
  [0D48:1794][2015-10-20T19:36:47]e000: MUX:  Exception: Info: Unable to load dynamic feed
  [0D48:1794][2015-10-20T19:36:47]e000: MUX:  ERROR: Could not load file or assembly 'System.Security, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The module was expected to contain an assembly manifest.
  [0D48:1794][2015-10-20T19:36:47]e000: MUX:  Stack:    at Microsoft.Web.PlatformInstaller.Util.IsSignatureValid(String xmlFile)
     at Microsoft.Web.PlatformInstaller.ProductManager.LoadFromXml(String xmlFile, Boolean loadEnclosures, Boolean isOnlineFeedLoaded, Boolean verifySignature)
     at Microsoft.Web.PlatformInstaller.ProductManager.Load(Uri productFileUrl, Boolean filterByArchitectureAndOS, Boolean loadEnclosures, Boolean useCachedVersion, String cacheDirectory, Architecture architecture, Int32 osType, String&amp; finalFeedCacheLocation, Boolean&amp; isOnlineFeedLoaded, Boolean&amp; onlineFeedLoadError, String localFeed, Boolean verifySignature, String feedUri, String lastUsedFeedLocationKey, BundleProperties currentBundle)
     at Microsoft.Web.PlatformInstaller.ProductManager.Load(Uri productFileUrl, Boolean filterByArchitectureAndOS, Boolean loadEnclosures, Boolean useCachedVersion, String cacheDirectory, String&amp; finalFeedCacheLocation, Boolean&amp; isOnlineFeedLoaded, Boolean&amp; onlineFeedLoadError, String localFeed, Boolean verifySignature, String feedUri, String lastUsedFeedLocationKey, BundleProperties currentBundle)
     at Microsoft.Devdiv.Bootstrapper.Utility.SecondaryInstallerUtility.LoadProductManager()
  [0D48:05C8][2015-10-20T19:36:54]i000: MUX:  View loaded
  [0D48:05C8][2015-10-20T19:36:54]i000: MUX:  Go to Blocker page.
  [0D48:05C8][2015-10-20T19:36:54]i199: Detect complete, result: 0x0
  </code></pre>
  
  <p>Apparently, the problem is in:</p>
  
  <pre class="lang-bash prettyprint-override"><code>Could not load file or assembly 
       'System.Security, Version=2.0.0.0, Culture=neutral, 
        PublicKeyToken=b03f5f7f11d50a3a'
  </code></pre>
  
  <p><strong>UPDATE</strong></p>
  
  <p>After <em>devlin carnate</em> suggestion and reading answers from <a href="https://social.msdn.microsoft.com/Forums/vstudio/en-US/49f51101-9769-4ba6-8ab5-ec99debac917/visual-studio-installation-fails-with-cannot-load-systemsecurity?forum=vssetup" rel="nofollow noreferrer">this site</a> and <a href="https://social.msdn.microsoft.com/Forums/sqlserver/en-US/a8c09bf0-9b82-416e-90f8-05f3d5cdb90a/vs2015-community-setup-crashes?forum=vssetup" rel="nofollow noreferrer">this one</a> too I have tried the following:</p>
  
  <ul>
  <li><p><strong>Update my OS</strong>. Except for the "update to W10" I have installed all updates (even some of those marked as <em>optionals</em>).</p></li>
  <li><p><strong>Run a "scan now" from command prompt</strong>, bassically, I followed instructions from <a href="https://support.microsoft.com/en-us/kb/929833" rel="nofollow noreferrer">this site</a>, and even when something were marked as <em>corrupted</em> I don't know how to repair it ('cause no dll or file were detected).</p></li>
  <li><p><strong>Uninstall the .NET Framework and install a prev version</strong> (from 4.5 to 4) but the problem persist (also, after this, windows suggest to update to 4.5 so I reinstall 4.5 version).</p></li>
  <li><p><strong>Use the <a href="http://www.microsoft.com/en-us/download/details.aspx?id=30135" rel="nofollow noreferrer">.NET Framework Repair Tool</a></strong> with no results.</p></li>
  </ul>
  
  <p><strong>UPDATE 2</strong></p>
  
  <p>I just format my HDD unit and reinstall (the same) W7 SP1 all over again, after that, I was able to install VS Community Edition, but I don't take this as a solution since is just too drastic and I don't know the original reason of why this happened in the first place.</p>