OpenGL SDK

This may sound stupid but? Where can i get the OpenGL SDK? Does it have one? I dont rember. For the longest of time i have had the gl headers and libs on my computer. Now that i dont i need them, and dont know whre to get them. Any help would be great.I dont do much with graphics. I usalley handled the AI. Now I here of this shader stuff for opengl and decided to get into it. But low and behold i dont have the headers anymore. So I NEED THEM.

Thnx

If you install Visual C or Mingw or some other software equal, in the directory of this software you will find the libraries and header!!
See here
Bye