PCW_X.H

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

d:\th\minkernel\ntos\inc

and draws from it the following type definitions:

Line Number	Type	WDM.H	NTOSP.H
37	struct _PCW_COUNTER_DESCRIPTOR	40345	40251
44	struct _PCW_DATA	40352	40258
49	struct _PCW_COUNTER_INFORMATION	40357	40263
54	struct _PCW_MASK_INFORMATION	40362	40268
63	union _PCW_CALLBACK_INFORMATION	40371	40277
70	enum _PCW_CALLBACK_TYPE	40378	40284
87	struct _PCW_REGISTRATION_INFORMATION	40395	40301

The header PCW_X.H is not known in any Device Driver Kit (DDK) or Windows Driver Kit (WDK).