Hmm.. Well, since you are running a Domain, you have a Domain Controller.
Most Admins will install the DNS server on top of the DC, so that is where
you look first. It will be under Start > Administrative Tools > DNS
Then take a look at your Forward Lookup Zone. All computers that are joined
to a Domain will have a record there indicating the Name and IpAddress where
it can be reached. DNS provides name resolution (to IPAddress) so other
computers can find the one they need to reach.
Actually, I am a little surprised that you are running a Domain without
someone to manage it. Or was this left up to you?

--
FE
Wm P
MVP Microsoft Networking
MCP | CCNA | A+
"Ken W" wrote:
> I'm not a technical person. Where do I look for those DNS addresses?
>
> "Fatal_Exception" wrote:
>
> > Ken, we need a little more info first..
> >
> > When you say 'explorer' I assume you mean Network (Center on Vista, Places
> > on XP)?
> >
> > What computers are not showing up? Vista or XP?
> >
> > Might want to check DNS and make sure that there are entries in the Look
> > Zone for the missing systems also.
> >
> >
> > --
> > FE
> > Wm P
> > MVP Microsoft Networking
> > MCP | CCNA | A+
> >
> >
> >
> > "Ken W" wrote:
> >
> > > We have multiple computers that are part of a domain. One computer doesn't
> > > show up in Windows Explorer. Why-what do I need to do?