To be fair, Kenny, your PC system does sound a bit screwed up, considering I actually had WinXP (Pro) running on a 5 year old K6-II 350 with 128Mb (100MHz FSB) at one point.
Yes, I've used Windows XP on a similar setup (K6-II 450, 384Mb) and it was nowhere near the slowness KennyR describes. On that system IE6 loaded in less than 1 second, and that computer was several times slower than an Athlon. Actually, I tried a lot of Windows versions on that machine and XP (with the candy look disabled) was actually the fastest on it, faster than both Win95, ME and 2000, especially when running games.
I've run Win2000 on a 64Mb P133, and that was still faster than what Kenny describes.
Something must have gone horribly wrong with XP on that machine, I'd try a complete reinstall.
WinXP on my 1.8GHz Pentium IV 512Mb rdram is actually more responsive now than my old AGA A1200 with a 060 is, even with the candy stuff turned on (I still prefer AOS though).