You could try downloading and running the Upgrade Advisor:
http://www.microsoft.com/windowsxp/pro/howtobuy/upgrading/advisor.asp
(It's a bit large if you're limited to a dialup modem.)
Assuming that it's compatible, you may have to turn off some of the XP
graphics features to get acceptable performance. (That stuff just makes the
interfaces look slicker; you won't need it.) XP isn't as friendly towards
"legacy" interfaces (especially ISA) as was Win9x, but they are still
supported. Some peripheral manufacturers have never bothered to produced
drivers for XP (or Win2k), so make sure that all of the devices you wish to
keep have XP drivers available. (Some peripherals, like older HP Deskjet
printers, have drivers built into XP that will allow them to be used, but
they are highly simplified compared to the previous drivers.)
I haven't run XP on a PII, but it may be worth the risk.
One caution: while XP is supposed to be an NT variant that is finally ready
for mass-market use, it's still more complex to configure than Win9x. There
are many settings choices in XP; so many, in fact, that there is a transfer
wizard to allow you to copy settings when you switch to a new machine.
Good luck.
Bob Knowlden
Address may be altered to avoid spam. Replace nkbob with bobkn.