Also if you want to boost your fps up in-game, you can try downloading GameBooster.( Game Booster | Faster Play, Free Download | Free Game Accelerator Download
) It's pretty useful if your running on a low-spec-computer. I use it myself.
Basically what it does is that it shuts the unnecessary properties that would lower your fps (backround-programs, graphic-settings) with 1 click. After your playing session is over, you can just click the same button to go back to normal. It's very convient.
Oh and the OpenGL, I think you can turn it on at Counter-Strike - Options - Video by choosing the bar where you see d3d or Software, just press it and change to OpenGL.