include libraries not working

Granted, I don’t know much about OpenGL or C++, but I’m getting problems just copying beginning code out of the guide. For some reason I get a number of errors when I build anything with <GL/gl.h>. They include:
C2501: ‘WINGDIAPI’ : missing storage-class or type specifiers
C2086: ‘int WINGDIAPI’ : redefinition
C2144: syntax error : ‘void’ should be preceded by ‘;’
among others. If I could get some insight to this, it would be greatly appreciated. Thanks

Try to put #include <windows.h> before or after gl.h.