Customizing layout.inf - how?

[Nameless Mofo]

I searched far and wide for an answer to my question, but no good answer found so I'll ask it here hoping Nuhi may know the answer.

I want to customize my layout.inf (XP SP2) but when I do, setup fails due to layout.inf being signed and it fails the sig check. I believe the sig for this file is in nt5inf.cat.

I read on some other msfn boards that a tiny hack to setupapi.dll will stop it from checking signatures during setup, allowing customized layout.inf. But the hack was only good for win2k3 sp1, not xp sp2.

If anyone knows how to modify either setupapi.dll or syssetup.dll to accomplish this feat I would very very much appreciate it!