All this talk of downloading drivers for your modem. You will find, as we
all have done I am sure, that once you do work on your computer that has the
effect of breaking your connection to the internet (e.g. modem not working)
you will ask yourself "why didn't I download all of that stuff when I had
connectivity!". I.e before the upgrade work began.

I continue to find
that it helps having a 2nd (or 3rd) computer very close by which I can use
to surf the net to get me out of the holes I dig for myself (as recently as
yesterday).
There may be some applications such as certain games and other "media
intentive" apps that simply don't run on Windows 2000. Check the boxes or go
to the app vendor site and check to see what apps will not run on W2K. If
there are some that won't run and that you just cannot live without, then an
upgrade is out of the question.
They key is to do all of the hard work before you start the upgrade, then
the upgrade will go somewhat more smoothly.
Unc