So actually you can see the external drive on your XP MCE but after you
select it and click OK, it ask you for username and password, right? If so,
could you try some username like Administrator or Admin and use empty
password? Is there any user acounts from Control Panel->Users? You can try
some of those too.

"REW2705" <REW2705@discussions.microsoft.com> wrote in message
news:B581F1CA-AB0E-495D-8B12-8B7B647186D4@microsoft.com...[color=blue]
>I am using a laptop with Vista Home Premium. I am attempting to use the
>Back
> Up Files utlity to back up to a external drive attached to a XP Media
> Center
> Ed PC on my network. Sharing has been enabled on the drive, and I am able
> to
> write and read from the laptop with no problems. The drive does not appear
> as
> an option in the "On a hard disk, CD or DVD:" option, and when selecting
> the
> drive from the "On a network:" option, I am prompted for a user name and
> password. The drive is not password protected and I do not use user names
> and
> passwords on the XP PC. Is there any reason why I can not back up to this
> drive?? The common exceptions listed in the FAQ do not seem to apply to my
> case.[/color]