I'm not a broadband user, but I would hazzard a guess that in order for your PC to communicate with the broadband connection (what type have you got? ADSL, Cable) the Microsoft "Networking" element of Windows 98 has been installed.

The result is the login screen that you see every time you re-boot the machine.

It will appear every time you boot.

As far as I know you can't get rid of it (though one of the more Windows-oriented techs on this site may have something to say - I'm just an Internet person).

Hitting escape to get rid of it won't affect your connection to the Internet.

The object behind it is so that you can have different users log into the machine with their own username and password and then have separate areas on the hard disk to store their mail, documents etc... However, pressing escape overrides it, so in Windows 98 it's pretty useless.

You could try pressing OK next time the prompt comes up but don't fill in any of the boxes..think thats how I got rid of it.

I kept getting that but after I got that virus and all my machine was cleared it went and luckily I no longer get it as it was a bit annoying.