problem accessing computer on network

I have a home network with 3 computers. One running Vista and the other 2
with XP. the 2 computers with XP can access each other and the computer with
Vista, but the Vista computer can only access one of the XP computers, when I
try to access the other computer a box pops up asking for a user name and
password. No usernames or passwords were ever set up on any of the XP
machines.

Hopefully someone can tell me how to access the rouge machine

TIA
Duncan

I just turned on the computer today and can access all the computers on the
network. I have no idea why? as all the settings are the same.

"duncanh" wrote:

> I have a home network with 3 computers. One running Vista and the other 2
> with XP. the 2 computers with XP can access each other and the computer with
> Vista, but the Vista computer can only access one of the XP computers, when I
> try to access the other computer a box pops up asking for a user name and
> password. No usernames or passwords were ever set up on any of the XP
> machines.
>
> Hopefully someone can tell me how to access the rouge machine
>
> TIA
> Duncan