A while back I blawgd about how to get the MSDN library for offline use. However, the Help Viewer has its problems. I won't list all of its problems, but it was certainly a bad candidate to integrate Win32 API documentation support to Ghidra. There is a pretty neat project by Laurence Jackson, but I think I just found something a little better even: Microsoft provides a download of the MSDN Library for Visual Studio 2008 SP1, stand-alone, offline, as an ISO - smell this, Help Viewer:

So this is nice, but the main point of this exercise was to integrate this into Ghidra. If that's something you care about, read on.