Waiting on Registry

From: Borland (ifcc_at_earthlink.net)
Date: 12/31/03 

Date: Wed, 31 Dec 2003 13:08:59 -0600

I recall Windows has the ability to 'wait on a registry change'. I want to
use it in a service. I can't seem to find the function in the Windows SDK.
Can anyone remind me where it is ?

TIA