To disable storage of network passwords.
The Network passwords by saved , if u save the password in the dialog box.. u can view the setting in the follwoing location
Click Start and open Run
In that window type: control userpasswords2
in the next window go to the secon tab on top, named: Advanced
and from there open: Manage Passwords
There you should see if there is a password stored for the address that you have mentioned
If yes then delete it and close the windows with OK
try to connect again to that address, it should prompt for authentication. Do not check the Remember option…
For Disabling the save password option
In Windows XP go to “Control Panel > Administrative Tools” Double click “Local Security Policy” mmc snap-in Shortcut.
Now in “Local Security Policy” management console open “Local Policies > Security Options” on your left.
You will see a Policy list to your right. Browse to the Policy “Network access: Do not allow storage of credentials or .NET Passports for network authentication”. Double click it, select Enabled, click Apply and then OK.
Reboot your computer.
Please Note: Passwords will be remembered until you logoff or reboot.