I have a HP P4 2G single core running XP Home SP3. It works well, and gives me few problems. I also have a Dell laptop that has a slightly faster processor that runs XP Pro SP3. They both seem to work fine. I bought the laptop from a friend (who it turns out was having intermittent problems with it turning off due to heating problems) for $100, and when its infrequent problem got worse I found a complete set of directions (for my exact model, with pictures) on the internet, showing how to take it apart and clean the cooling system. It now works perfectly. I am not a hurry to change operating systems or computers. Some time ago, I came to the conclusion that it can pay to stay a couple of steps back from the latest operating system, and every time I get the urge to "upgrade" I remind myself that what I have does everything that I use it for well, although I plan to make one change. I am through getting ripped off by HP for printer ink. Next time I am trying having my cartridges refilled.