Missing .h files on compilation

Hi,
I’m a complete beginner here and following the tutorial for the plugin. I’m getting a couple of compile errors. One for GL\gl.h not being found, but it is here
C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\um\gl
and the other for windows.h, which I can’t find in C:\Program Files (x86)\Microsoft SDKs.
I’ve changed the Windows Target Platform to 10.0.18362.0, cleaned and rebuilt but I’m still getting the same errors.
Colin.