Windows Xp.... :(

That's the reason number one NOT to jump to new shiny OS !

To get drivers for WinME from the beginning was a nightmare (ATI cards not supported, Voodoo drivers crashed, USR modems and so on ...).
I'm pretty sure it's going to be the same way with XP, cause programming drivers is pretty expensive, so some HW manufacturers will NOT have drivers for WinXP for long time.

Now about your problem mlhlmh ...
What's for you need VIA master bus IDE drivers, if it works without it ?
As for W98 you don't need it (I don't know bout XP, but my guess it's all the same). More than that, if you'll install the wrong thing, serious skills would be required to remove it.
Enjoy what you've got


Good luck
Chef

P.S. I prefer to use licensed software too, but what can you do