Your HP Pavillion 8562,PentiumIII 500Mhz processor is a good machine, but I don't know how to make it faster, except to clean out all programs you do not use. Look at your Processes to see what is running, and which programs use a lot of memory. Remove all software you can that runs in background.
Your HP was designed as an office and email machine... not a gamer. Pentium III machines are rugged and last forever, but they are not very fast at 500 MHz, and do not change much when you tweak them.
Be sure your CPU fan is clean, and the blades on your power supply are clean... using Queue Tips and a little alcohol.
Generally, if it freezes, that is a memory limitation, rather than a CPU... If you have the maximum of 384 MB, you are done. Time to stop eating and walk to work so you can use the food and gas money for a new and better computer...