core.sys.windows so lean?

[Jonathan Marler via Digitalmars-d-learn]

I'm writing some platform specific D code and I've found that 
what the druntime exposes for the windows platform is pretty 
lean.  I'm guessing that the purpose of the druntime version of 
the windows api is to implement the minimum required to support 
the windows platform and not meant to be a full-featured 
interface to windows.  Is this the case?

If so, is there a good library that someone has implemented to 
support the full windows API? I think I remember there was one a 
few years ago, but now I'm unable to find it.  I think I remember 
that the windows .lib files installed with dmd were missing 
symbols/functions I needed so I had to use the ones in the 
system32 directory installed with windows.  I also had to convert 
them to OMF (since optlink doesn't support COFF).  I'm just 
wondering if someone can shed some light on this, it's just been 
a while and google didn't seem to be much help so pointers in the 
right direction would be much appreciated.  Thanks.