Use riva tuner instead, if you use ati tool it creates a utility driver in system devices and its difficult to remove, riva tuner dynamicly overclocks the memory on the gpu by altering the timing ati tool does not do this so you cant get a decent memory overclock out of it, overall i get a much better (and stable) overclock out of this programme, it is a bit more difficult to use though, it also works with vista!
Erm.... with ATITool u can change the power supply to ur card, and its a deafult "standard" status that the program starts with but u can make a personal one tat u can save so you just have to load it.
Its very easy i hasnt tested riva tuner but im pretty happy with ATITool.