network services and users accounts

I have encountered a problem with my network list service and network
awareness services not starting. I am getting an error 5 - access denied. I
would like to put all of these services under a specific account and control
the user they run under. But - there are dependencies that are saying the
services will now not start because they are dependent on a service running
under a different user! The service they depend on seems to be the RPC
service which runs under network service and can not be changed. These others
were not originally under network services user! Any advice - am I totally
hosed now? I can not reinstall Vista as I have no disks - came with the
system! I am about to give up and go and install XP Pro which is much
simpler! Thanks for any advice!