Updated screencasts for installing and updating gprMax.

docs/source/screencasts.rst

@@ -9,7 +9,10 @@ This section provides links to screencasts and videos that explain how to instal
 Installation
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-* `How to install gprMax for end users on Microsoft Windows <https://youtu.be/dvC0_7qFVbE>`_ -- Needs updating for new unified installation procedure (30/05/2016)
+These screencasts are demonstrated on Microsoft Windows 7, but the installation and updating procedure is the same for other versions of Windows, and quite similar for Linux and Mac OS X also. Detailed written installation and updating instructions are provided in the Getting Started section.
+
+* `How to install gprMax on Microsoft Windows <https://youtu.be/YkPWMmJILcI>`_
+* `How to update gprMax on Microsoft Windows <https://youtu.be/e0ROY792s9o>`_
 
 Visualise EM wave propagation
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