A fresh install of windows will usually make it run faster if you haven't done it since you have had the computer, that system is quite old. You should add at least another 512 mb of memory. Check your startup programs for anything that don't need to be running on bootup. You could also have malware infections. There are a lot of different reasons. Can you please explain more in detail on what is actually slow. Is it booting? the internet? running apps?