This behavior occurs typically for users who log onto the target computer for the first time, and can also occur for users who are creating a new user profile on the target computer.
When the user profile is first created, the Internet Explorer connection settings will not be considered to be fully configured until the browser is first opened by the user. Before that interactive process can occur, the Windows Group Policy subsystem will apply the appropriate policy and customization settings before the user is permitted to interact with the desktop environment.
Once the user has the ability to interact with the desktop, the default Internet Explorer customizations will have occurred as well as any customizations implemented by the IEAK (Internet Explorer Administration Kit). As soon as the user launches Internet Explorer for the first time, a connection setting migration procedure takes place.
As part of this setting migration, connection customizations such as the state of the Automatically detect settings, Use an automatic configuration script, Use a proxy server and applicable Dial-Up values will be reconciled with any available connections defined on the Internet Explorer Connections tab. One step in this migration process involves the explicit enabling of the Automatically detect settings option for the default connection so that the value will be copied to any additional dial-up connection entries that may be present.
This migration procedure is controlled by the state of the MigrateProxy DWORD value found under:
By default, the value is ‘0’, which indicates that the procedure has not yet been executed. The value will be changed to ‘1’ when the procedure completes.
NOTE: The application of an IE Maintenance connection settings group policy will not affect the state of this procedure.
If the user profile is configured for deletion upon logoff, it may be necessary to deploy a custom group policy or user login script to redefine the MigrateProxy value from 0 to 1 and bypass the migration process entirely.
NOTE: If this migration process is prevented, the default LAN connection settings may not be replicated as expected to the existing dial-up or VPN entries listed on the Internet Explorer Connections tab.