Vista - Simple File sharing on Vista as it was on XP...possibe or not?

I read that the simple file sharing was stoped on Vista but if i share an
external USB2 hard disk i can acess it from other systems with Vista or XP
without setting any accounts on Vista OS...can some one explain to me how
was this possible? Even i set the accounts on Vista from an administrator
account of an XP system, i can't acess the shares on
Vista...this is not working as it was a domain in 2k or 2k3...there aren't
the same tools and options...can some one
give me some tips about this new sharing system in Vista.

Txs all.

File and Printer Sharing in Windows Vista
http://www.microsoft.com/technet/net.../vista_fp.mspx

"MeatWar" <ng55896b@iol.pt> wrote in message
news:%23U7%23jbhaHHA.4856@TK2MSFTNGP03.phx.gbl...
>I read that the simple file sharing was stoped on Vista but if i share an
>external USB2 hard disk i can acess it from other systems with Vista or XP
>without setting any accounts on Vista OS...can some one explain to me how
>was this possible? Even i set the accounts on Vista from an administrator
>account of an XP system, i can't acess the shares on
> Vista...this is not working as it was a domain in 2k or 2k3...there aren't
> the same tools and options...can some one
> give me some tips about this new sharing system in Vista.
>
> Txs all.