Hi cyrilgourmelen, WebGL is a graphical language that some sites use. In order for Firefox to run WebGL, it needs a compatible graphics card/chipset driver. I suspect you have an older system if you are running Windows XP, so your driver software might be somewhat out-of-date. Could you check the following article to see whether it helps you find an update? Beware of dangerous downloads on unofficial sites and stick to Microsoft and your computer manufacturer, as well as the graphics card/chipset manufacturer (e.g., Intel, AMD, Nvidia). [[Upgrade your graphics drivers to use hardware acceleration and WebGL]]