"weird error"

hi, i know this isnt a ADVANCED question, but they cant give an answer.
I was having errors in gl.h, and some guy told me to include windows.h before it and it solved the problem. But now iam getting this:
c:\c-cpp\opengl\xeya\loadtext.h(87) : error C2065: ‘GL_TEXTURE_3D’ : undeclared identifier

i also get it in everything related to 3D, like glTextImage3D, GL_R, GL_WRAP_R, etc…
i really need an answer soon, thanks for any ideas.

give it a bit more time, I posted a reply to your topic in the beginners forum