half-life & co

Hye, my name is Willy and I’m new here:P
I have a problem with the videomode of half-life and co. When I first got half-life I could play it in opnglmode but now I only can play it in software mode

Oh, and whenever I try to change the videomode in d3d or opengl the screen turns back to the desktop with a message you only can run it in software mode or something like it… help me please?
the graphics in software mode gives me nightmares… :stuck_out_tongue: