windows xp manages the page file ,it can be a different size every time you look, i think , do i think you should upgrade you processor t o 1 gig ,no, waste of money in my opinion and a 500 that you have now running xp and 128 meg ram ,is just totally nuts !,get something bigger computer are cheap now . unless you are running a AMD processor you will need to get a new motherboard to go from 500 ,to 1 gig anyway