Not endorsing this setup, but if you bought a computer for your CNC that does not support a high-enough version of OpenGL, then you could try this pre-compiled installer for Mesa 3D, a software OpenGL emulation: https://github.com/pal1000/mesa-dist-win/releases . It was fast enough at 1280x1024 on an Intel Core 2 Duo with Intel G43/45 onboard graphics. May be worth a try. No endorsement.
[ I replaced my Mach3 setup and that PC was much older. I didn't put much thought into what PC to buy since this used Core 2 Duo sure was faster than my old one … ]
[ I typed this before but the post didn't show up. If you find duplicates now, just delete one or both. ]