A Paging file is used instead of ram when your Ram gets full. The paging file is stored on your hard drive so it will be slow to access. I recommend a paging file 1.5x your ram size
Jason's right. Plus you should also keep the gap between initial and max to a minimum. I usually have both set the same. This, among other things, makes sure that the page file is initiallized to the maximum set from the beginning regardless of use.
