Newbie here trying to give you some hope.
I've been running Windows Xampp since Christmas and been having lots of fun. No memory problems, no performance problems. All of package running together all day long with addons, for days without a need to shut down.
This is on a WindowsXP SP2 P4 Laptop with a 20GB drive and 512mb 64 of that going to video.
If XAMPP is doing this something must somehow be misconfigured on your system. Mismatched versions, a bad httpd, could be alot of things and in my experience it is usually windows.
Are you running Apache and MySQL as windows installed services as suggested?
Have you done a search right here for "memory+ pagefile" Search all of the groups and go to google language to translate.
I'm no genuis, but I do know there are alot of thing that can go wrong with a web server if you don't know how.
I got thru my installation with just what was available at apachefriends and doing a little research before I before I started on the next step.
Have you gone thru readmes and documentation here and on the net.
If I see something that will help you I'll bring it here.
good luck to you.
Here what my task manager looks like. Image coming from my laptop. hope it works!