Returns the default directories for midl to search for imported idl files.
You can call
midl-default-import-paths to see what paths midl is going to use. Microsoft do not actually document where you should be looking for imported files, so there is an element of guessing in
midl-default-import-paths, but if you install the Windows SDK in the default place it should work.
LispWorks COM/Automation User Guide and Reference Manual - 14 Feb 2015