to disable paging file:
right click "my computer"
-> settings - under "Performance"
-> change - under Virtual Memory
click "no paging file"
click "set" then "apply"
restart your computer
paging file is a part of the hard drive XP uses in place of RAM. but hard drives are much slower than RAM, so by disabling paging file, things should run faster.
prefetch is just copies of programs loaded by Windows on boot, so that if you wanted to run those programs, they are already in RAM.
however, what this does is take up more RAM (XP is pretty bad at managing RAM), and thus reducing overall performance.
it also slows boot-up time, because it is loading extra stuff.
you can set up a script to delete the prefetch every shutdown. you need 2000 Pro or XP Pro (not Home)
open notepad, and type in:
del C:\Windows\Prefetch\*.* /q
go to save as, give the file any name, but make sure it has the extension .bat (for example "file.bat") (you also need to select "all files" in the "Save as type" list)
go to start, run and run gpedit.msc (XP Home does not come with it)
under "computer configuration" go to "Windows Settings"
then go to "Scripts (Startup/Shutdown)"
go to "Shutdown"
in the new window, click "add"
browse to the file you created, and add it. then exit the group policy editor.
now, on every shutdown, the prefetch will be deleted.