Auto PowerOn/Shutdown via DC

So here is the question I am trying to config a solution to shutdown and wake up workstations via the network I manage, earlier I beleive that I could create a batch file that would run from the server, I know that I used to do this using earlier models of NT. When pushing software updates and restarts. Any suggestions?

Op server Win 2003
clients all vista with 1 xp.

Any ideas would be greatly appreciated.