Right click My Network Places/Properties/Advanced (top toolbar)/Dial-Up
Preferences/Enable Auto-Dial by Location/Uncheck all locations and check off
always ask me before auto dialing. Also, Disable autodial while I am logged
on.
In the Enable Auto-Dial By Location dialog box, select each location for
which you want the automatic dialing feature to operate. Reboot.
Also, in IE/Tools/Internet Options/Connects/Never Dial
Disable or Enable AutoDial (Line 91)
http://www.kellys-korner-xp.com/xp_tweaks.htm
To view the list of names and addresses recorded by AutoDial, type the
following command at a command prompt: rasautou -s
To delete a name or address entry from the list: Start/Run/Regedit
HKEY_CURRENT_USER\Software\Microsoft\RAS Autodial\Addresses
You can delete any TCP/IP addresses that you see under this key. Note that
AutoDial can use IP addresses, DNS fully qualified domain names (FQDN), and
NetBIOS names.
Disable "Log on using dial-up connection" (Line 77)
http://www.kellys-korner-xp.com/xp_tweaks.htm