Do you want to use OpenGL API directly under Windows OS ? If so you will need to use GLEW in order to get the OpenGL functionality supported by your driver.
Since I don't use Windows OS on any of my computers I can't help you more than that.
Best regards
StarBootics
The Stone Age did not end due to a shortage of stones !
I got the same problem. An old project with openGL now opened with PureBasic 6.02 for Windows, x64. PureBasic syntax check/compiler says it cannot find the subsystem and does not compile. If I remove openGL in the compileroptions (libs), it does compile without warning or errors, but the executable gives a Warning: Please compile With OpenGL subsystem. Then the exe stops, so it is not only a warning. What can I do about it? Any help much appreciated.
The OpenGL subsystem has been made by default, so it's removed (the DirectX9 subsystem appeared). You just need to find in your code where is the check for the OpenGL subsystem and remove it.