title: Cannot install Nuget Package Manager
body: <p>I am using VS2010 on Windows 7 (64 bits). When trying to install "Nuget Package Manager" from VS's "Extension Manager" it fails. The download works, but then I am stuck at the installing progress bar. When looking  in Windows' task manager yo can see that the installer keeps on starting up new instances of the "vsixinstaller.exe" process. It goes on and on until the computer ultimately crashes.</p>
  
  <p>The same behaviour occurrs when starting the file "NuGet.Tools.vsix" directly.</p>
  
  <p>I have searched the net for the solution but haven't been able to find anything useful.</p>