One of the issues you may need to consider is the type of processor you are using. If you have a Celeron and your board will support a P4, then you should do that. My system is running an AMD Athlon XP 2700 Thoroughbred. I have 512 RAM, an ATI video card 128mb. Except for very large gif files I have no lag at all. The problem may not be your processor, it maybe the lack of a firewall and anti-virus updates. Even with lots of precautions it is still possible to pick up a virus or spyware which does really bog down the system. Defragging will not get rid of that trouble. But regarding the processor, AMD does a great job of handling graphics. Make sure you are installing all your Windows Updates, back up your data. Windows XP Professional over XP Home has fewer problems. The only problem PI has for me is it doesn't like to open saved files from my Zip Disk.