This can be caused by an application attempting to connect to the Internet
in the background. Things such as Instant Messaging applications as well
as applications that check the Internet for updates (antivirus, spyware,
You may want to try running MSCONFIG from the Start | Run line and then
selecting a 'Selective startup' and not processing any of the startup
items. Reboot and confirm whether the prompting still occurs. If it
doesn't, then there is an application causing this demand-dial behavior.
Let us know if there is more we can do for you...
-Joel Baxter [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.