Invalid dynamic link call to a .dll file

I am trying to set up a wireless home network. My base
station is on a pc in my living room (running WinXP) on
which I am running broadband. I am trying to set up a
wireless adaptor on my son's pc in his room (next door to
the living room,running Win98SE). The USB port on his PC
is a 1.0 or 1.1, and the system requirements for the MN-
710 adaptor says this is acceptable, although faster
performance can be achieved with a 2.0 port. I get
through the installation, up to the point where I
actually connect the adaptor to the port, then I keep
getting a program error: "Your program is making an
invalid dynamic link call to a .dll file", and I have to
close the installation window. I found this error
associated with other programs in the Microsoft Knowledge
Base, but I am unable to find it tied to my adaptor. All
status lights are on. If I leave the adaptor hooked up
and reboot the pc with the adaptor connected, I am unable
to reboot completely (the wallpaper screen without any
other desktop icons or start-up toolbar appears).