HelpArma 2 isn't working why?

I downloaded the game and once I start it it says "Error: Shader model 2 not supported anymore".
I don't get it.

Have you updated to patch 1.62? Link is here Arma 2: CO / OA / Reinforcements Patch 1.62 - Official Patches - Armaholic. If you got it through steam I'd recommend reinstalling or validating your game files. Also make sure you are on the newest beta patch for Arma 2. Programs such as DayZ Commander can assist you in making sure everything is kept up to date.