WDBGEXTS.H

The public symbol file NTKRPAMP.PDB for the original release of Windows 10 tells that the kernel is built with the WDBGEXTS.H header at

d:\th.public.fre\sdk\inc

and draws from it the type definitions that are tabulated below.

Nowadays, WDBGEXTS.H is among the headers in the Software Development Kit (SDK) for Windows 10. It is there in the “um” subdirectory with many other headers that are intended only for user-mode programming. Before the SDK for Windows 8, WDBGEXTS.H is supplied with the Windows Driver Kit (WDK) and earlier with the Device Driver Kit (DDK). But not too early. Before the DDK for Windows 2000, the header was instead with the SDK.