Power Saving setup on XP connected to a Domain (Windows2003 Server)

Hi,

I have recently added 2 XP pro. PCs on a Domain, and I can't remember
anymore how to set Power Saving parameters on each machine. When I try to
change, I get an error message saying that I don't have the rights (although
this account has administrator rights).

Additional question: from where are the default parameter (others than those
set with a local account on the machine) taken? Probably somewhere from the
Windows2003 Server?

Thanks,
Hubert Retif