Well, I can tell you without a shadow of a doubt that Atremis is correct with his assessment on the paging file and xp. You don't turn it off, period. It's not meant to be off, and for anyone to recommend that when your not aware of the level of experitise of the reader is unwise.
Yes, in new versions of windows, it can be a way to squeeze out a bit more performance, but there are several other things that should be visited first before you start getting down to that level.
What might be a good idea is to create a thread that has a checklist of things to go through when running games in general to help boost performance. You can do some small things; make sure your virus software is in sleep or game mode, things like turning off indexing and looking at unnessary programs in startup. If your getting to the point where your messing with paging files just to make the game run, and you've exhausted all other possibilies, your better off with an upgrade than you are to continue tweaking.
I just think people need to be a bit careful about what they go recommend to people when it potentially could cause their systems not to function properly.
As far as where I am with my graphics settings, I always like to start out at a place I know it will work and then push it up from there. That way I don't get to see where I could be and have it flaky, and then have to drop it down a few notches. If I run it low and like it, and it runs great, it can only get better!