title: Windows update caused MVC3 and MVC4 stop working
body: <p>am i the only one who installed a Windows Update (8.1) on october 15, and suddenly MVC stop working because of this warning?</p>
  
  <blockquote>
    <p>Warning    1   Could not resolve this reference. Could not locate the assembly "System.Web.Mvc, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.    </p>
  </blockquote>
  
  <p>It seems that this windows update installs a newer version of MVC with version number 4.0.0.1, and removes old version from program files folder.</p>
  
  <p>Someone know how to fix this without crawling for each project?</p>