Most nVidia\AMD graphics cards do support openCL version 1.2.
Sometimes, Windows decides to install a compatible driver from Microsoft that does work but doesn't support the openCL which is needed.
A replaceable driver should be installed, one from the original creator of the graphics card website.
nVidia drivers web page:
http://www.nvidia.com/Download/index.aspx?lang=en-us

AMD drivers web page:
http://support.amd.com/en-us/download

A clean installation should be performed by uninstalling Microsoft's drivers or checking the box inside the installer that says "clean installation".

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