All functions in the API-MS-Win-Service-winsvc-L1-1-0 set are exports from ADVAPI32:

For most of these functions, the implementations in ADVAPI32 version 6.1 and higher are just stubs which transfer the handling to wherever the schema redirects the API Set. The exceptions are:

which have no code in ADVAPI32 but are instead exported as forwards to the API Set.

New Locations

Non-trivial implementations of all functions in this API Set are exported from SECHOST version 6.1 and higher.

Schema Redirection

The Windows 7 schema redirects this API Set to SECHOST. Thus: