Multi-screen problems with HalfLife

I use two screens on my video card (Ati radeon 700 / VE) but, when I launch Half-Life, he says “You video card doesn’t support OpenGL”. Then I must disable it when I want to play…

But I use specials programs for my screens and I must close them to desactivate the screen 2 and relaunch then reconfigure them after…
Can I use OpenGL on HL without disabling the screen 2 ?

Thanks you to answer…