Networking Problem

I have posted on the techtv site as well and found others
that have the same problems there too. I was wondering if
it had to deal with different versions of xp, not just
home and pro because they were working fine before, but
different releases of pro. My two computers that are
running fine have earlier versions of xp that didn't have
the service pack with it. I just bought an oem version
with the new desktop I got which came with service pack
one on it already. Maybe this might be a problem? Do you
have the same situation. I was thinking maybe microsoft
upgrades might be an issue too but all of my computers
have all the same updates installed.