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