networking windows 98's with windows XP's

Hello everyone:

I have 6 computers and a DSL modem connected to a router and am able to
connect to the WWW with no problem from all of them. 2 computers run
windows 98. 3 run windows XP pro and the last one windows XP home.
All of the XP's browse each other. both 98's browse each other and one
of the XP pro's but not the other XP's. I remember when I got my first
XP (the one that can browse the 98's) someone showed me how to install
NETBUI on the XP. I have since forgotten how to do it. Is this the
solution (inatalling NETBUI on the XP's) or not? If yes, would someone
direct me how to do it.

Many Thanks,
Shahram Sheybany