I suggest you try one or both methods:
1) Run MSCONFIG and goto the startup items, uncheck that dial-up item.
2) Remove/delete that dial-up s/w then reboot. Re-install it again, but pay attention that "if" it asks, not to make it appear during start-up(auto) procedure.
One of those should correct it. However, if this is a recent distraction, then use the system's "restore feature" and pick a restore point when this didn't happen.
My daughter's work laptop keeps popping up a manual dial up box even when she is connected to the internet by high seed connection. HOW can she stop this from popping up every few seconds? It is very annoying. Thanks.