annoying auto dial-up connection request

i do use dial-up from my home for my laptop.
and wireless at my workplace.

it is fine when i m connected to internet.

But when i m not connected then it frequently ask to connect through dial-up connection pop-up.
It’s happening eventhough i m not trying to browse any pages… i think some application trying get the updates so these connection request are popping up.

Any Solution to stop these connection request????

I m running XP 5.1 (SP2)
browsers Mozilla and IE