title: How can Visual Studio determine a solution file's version?
body: <p>Think that I have two solutions: vs2009.sln and vs2010.sln. Both of solution files have the same extension (.sln) but they have different icons. And they are opened in the related version of visual studio. I wonder how does visual studio determine this?</p>
  
  <p>Edit:
  Visual studio version selecter is ok but i wonder how can the icon be different even the extensions are same? I used to know that every extension has only one icon in registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Current Version\explorer\Shell Icons</p>
  
  <p>2.Edit: I found the answer finally. If anyone wonders about that, the answer is here <a href="http://msdn.microsoft.com/en-us/library/cc144122%28VS.85%29.aspx">http://msdn.microsoft.com/en-us/library/cc144122%28VS.85%29.aspx</a></p>