title: Windows installer failing with error "Error writing to file: System.Web.Extensions.dll. Verify that you have access to that directory."
body: <p>I have a simple windows installer package that I created. All it does is install 2 .dll's into the GAC. This is a production machine, so as I understand it, it is a best practice to install to the GAC in this way (as opposed to using gacutil.exe, etc.)</p>
  
  <p>This installer works fine on another server that I have for testing. The server it works on, however, is just a plain vanilla installation of Win2k3, with nothing else installed. The production server this installer is failing on is a Win2k3 box with service packs, and a load of other software on it.</p>
  
  <p>I am not sure how to go about troubleshooting this. There are no events thrown in the even logs, etc. No indication of what is wrong. <a href="http://social.msdn.microsoft.com/forums/en-US/winformssetup/thread/c13c32d0-aaca-4547-a2cf-2d04ad13ef9a" rel="nofollow noreferrer">This question on MSDN</a> has some hints, but I can't seem to find any real answers.</p>
  
  <p><img src="https://i.stack.imgur.com/Y7sqG.jpg" alt="enter image description here"></p>