title: installer prerequisite in VS2010 Setup Project
body: <p>VS2010 Setup project, Excel AddIn, C#,  ExcelDNA, NetOffice </p>
  
  <ol>
  <li><p>I use VS2010 setup project to create installer. 
  Click Prerequisite properties of the setup project, I see Windows Installer 3.1 and Windows Installer 4.5 are listed in prerequisite list. 
  In VS2008, I checked Windows Installer 3.1 in prerequisite (though I do not know why?).
  In VS2010, I wonder maybe I should check windows installer 4.5 in prerequisite list. 
  I wonder if I need check it and why? </p></li>
  <li><p>Another thing is  Shared Add-in support Update for Microsoft .NET framework 2.0 (KB908002) is listed in prerequisites list, too.  Wonder if I need it? My AddIn is target .NET 35 Sp1</p></li>
  <li><p>My addIn target .NET framework 3.5 sp1 in VS2008, now I move to VS2010, in setup project, I can check either .NET 3.5 SP1 or .NET 4.0 as prerequisite.  Does my target .NET framework have to be the same version as that in prerequisite list?  </p></li>
  </ol>