How can I shorten this so that it doesn't need to run every boot. I currently have this in my GPO as a startup script for all my computers.

Code:
  
 $pdcname = "SOMERSET-DC"
 $computername = "%COMPUTERNAME%"

 $userstring = "LocalAdmins"
 $groupstring = "Administrators"
 $groupobj = GetObject("WinNT://" + $computername + "/" + $groupstring)
 $groupobj.add ("WinNT://" + $pdcname + "/" + $userstring)

 $userstring = "LocalPowerUsers"
 $groupstring = "Power Users"
 $groupobj = GetObject("WinNT://" + $computername + "/" + $groupstring)
 $groupobj.add ("WinNT://" + $pdcname + "/" + $userstring)

 $userstring = "LocalRDPUsers"
 $groupstring = "Remote Desktop Users"
 $groupobj = GetObject("WinNT://" + $computername + "/" + $groupstring)
 $groupobj.add ("WinNT://" + $pdcname + "/" + $userstring)



Thanks