OK, I'm probably opening a can of worms for myself here. I'm a PC Tech by trade, and as performance from one individual machine can vary so much (this is mainly because their is no such thing as a "standard model" and all desktop pc's are put together from various parts sourced from different manufacturers).
Anyway, my guess would be that this new laptop has very low system RAM (XP needs at least a gig to run comfortably), unfortunately this is usually the case with most PC, as I have even seen very high end machines, being built with low RAM. This is usually done to keep costs down.