[ddouglass]

John,
You mention SP3, do you also have Internet Explorer 7 and Windows Media Player 11 installed. Both programs are used and though you don't have to have the upgraded versions it does work better with them.
There are major differences between 4.0 (I assume you have got the latest 4.03) and the 3.4 version. The displays are produced with totally different components so it is like comparing apples and oranges.
Your C drive works the best and fastest if you try to keep around 50% of it free. The other drives don't need to have this much free, but they do need at least 25-30% free to be able to defrag them.
When your operating system was reloaded did they defrag the drive after that? Windows XP has one of the worst loading operating system Microsoft has ever produced. The fragmentation is so bad that even they recommend you defrag after loading.