ok there are many ways to increase speed 1# i say reformat ur drive and start fresh. since its a p111 u should probably get a lot of ram since it is fairly old i would get rid of whats in there and get some pretty decent stuff then if u built it u can overclock but i dont recomend that since it can cause system corruption by killing the chip but reformat and add some decent ram ull be good u cant really change the speed of the processor but u can the computer!
You can up the fsb in the bios which will raise the overall CPU speed as long as your motherboard supports it. YOU DONT HAVE TO REFORMAT. but i would have at least 512 in it if you are running XP.