keep in mind it may be "better", but it is still REALLY SLOOOOOOW. My 2.13Ghz goes between 4%-40% just running XP on it's own. Web browser brings it to 50%-60%, and very low settings on older games bring it to full load. I think rather than spend $40... I'd spend $100 and get a modern AMD platform @ 3.0Ghz+. Even though it's more money, it's much more cost effective IMO.
the pentium d's dont even cause a blip on the processor running windows 7...
i have a ton of open processes right now at least 20+ and im still only using 4%-9% cpu so im not sure how you are using 40% just on xp.
the only time i see my cpu maxed out is when running convertxtodvd...
these computers are 3.2 pentium d's with radeon 5600 & 2GB DDR2 800
changing 3 already built pc's completely to AMD is more than i want to do, i can get some 1.8 C2D for $30 each so thats $90 total to upgrade all 3 computers.
i dont want to spend $300 for sure.