Silverlight : Could not load file or assembly 'System.Windows, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e' or one of its depend

Very irritating!

and very similar to here:
http://bartwullems.blogspot.com/2010/08/could-not-load-file-or-assembly.html


Solved as follows:

cd C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\Silverlight\v4.0

gacutil /i System.Windows.dll

gacutil /i System.Core.dll