Questions about turning off Superfetch and Gaming Performace

Hello everyone!

I recently bought Crysis and have been running it on my laptop. I can play
the game with most settings on HIGH and just get a few slow downs when the
action is heavy. In the interest of of tweaking my performance to the
maximum, I was browsing about and saw someone mention that turning off the
Vista Superfetch feature improved their gameplay significantly.

Now I happen to like Vista's efficiency management, with the sole exception
that when I run a game like Crysis I want all background task at an absolute
minimum.

So my question has several parts:

How do I turn off Superfetch in Windows Vista Home Premium? Someone said you
could do this using the control panel. If your method involves the command
prompt or something intense, please list the steps in detail.

How do I turn Superfetch on again? And is there any wrong with continually
switching this feature on and off?

Is there a way I can set-up Superfetch so that it works with only certain
profiles on my computer. In other words, can I set-up a "Gaming" user profile
where Superfetch will remain off, and have Superfetch set to come on when I
access my primary profile? So basically I could just log off and log in again
when I wanted to play a game.