Where does Windows device enumeration actually begin?

That's in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum.

i.e., the PCI\ USB\ HID\ branches of a Device Instance ID path all originate from ControlSet\Enum.

That darn "libtoolize: AC_CONFIG_MACRO_DIR([m4]) conflicts with ACLOCAL_AMFLAGS=-I m4" error

Is caused by using CRLFs in Makefile.am. "m4<CR>" != "m4" and thus the libtoolize script will produce an error.

If you're using git, I strongly advise adding a .gitattributes file with the following:

*.sh     -crlf
*.ac     -crlf
*.am     -crlf