See the question and my original answer on StackOverflow

This online tool MagnumDb as "Magic Number Database" (disclaimer: I wrote it) is a totally free seach engine that contains 99% of Windows SDK constants with more than 70K guids (IID, CLSID, etc.).

You can query it by name or by value, using wildcards, etc., for example:

will get you this (name, type, value, SDK header file location):

IID_IChannelAudioVolume Guid    1c158861-b533-4b30-b1cf-e853e51c59b8    %ProgramFiles(x86)%\Windows Kits\10\Include\10.0.17134.0\um\Audioclient.h(1942,0)