Penetration Testing: Accessing Winxp shares

["Anurag Joshi" <mastermindanu () gmail com>]

Hi everybody,
     I have observed a couple of thing while pen testing a windows network. 
While i could connect to Win2000 machines using net use command(knowing the 
admin password) i could not do so on Winxp machines. How should one connect 
to default shares in WinXp?? Also that after installing SP2 in WinXp the 
default shares are not visible. Does this mean that there are no default 
shares available. Also that can we connect to default (ADMIN$) share from 
linux?? I tried to connect using smbclient but could not. In all the cases i 
was knowing admin password.
        Thanks for any help....
Anurag Joshi