OpenProcess() with PROCESS_SET_INFORMATION on protected processes

Hi there,

with the help of the TaskManager, I can change the process-affinity of
the svchost.exe processes. I need to click "Processes of all users"
and confirm the UAC-dialog, first, then it "just works" the set
the affinity.

I tried to do the same from within an application, which I start
via "Run as Administrator":

I find the process with "svchost.exe"-names and OpenProcess() it with
PROCESS_SET_INFORMATION. Well, the permission is denied, although
I am admin.

I could imagine that this is by design: Even administrators should not
be able to mess with protected processes. But how/why is the TaskManager
able to do this, then? Does it communicate with a kernel-module which
does the job, perhaps?

Regards,
Daniel Albuschat