Just for yet another two cent worth - If you are using Norton, that will slow you more than any other single program. Use AVG, it's better, and does NOT bog down the machine.
Spyware is another problem. Use Spyware Blaster, and Spybot Search & destroy. These two programs can help keep you running up to speed. TweakNow RegCleaner is about the best Registry cleaner I have found - & it's free.
Other than that, just watch what you install.
I'm running XP home/ SP2 on a Biostar mobo, with an old AMD 3200 64 CPU, with 2Gb RAM, 256Mb ATI 850 graphics card - and it is faster than you would believe.
