Dialup @ Bootup

Have you tried running msconfig to see what programs run at startup?

Check Internet Options, on the Connections tab, is it set to dial a connection whenever one is not present?

Chas

Can check -> start -> options -> control panel -> internet options -> connections -> highlight each connection and verify none are set to dial whenever a network connection is not present change to "never dial a connection" or "always dial my default connecion" (if it is the one you are using)

In IE Tools -> internet options -> connections repeat the process, except set them to "never dial a connection"

Don,
First is the other machine, sharing that dial-up?
If this just started perhaps someone installed an internet messenger service. You mentioned you use it to download e-mail. Perhpas that mail download application is set to dail the minute windows starts. This type of application will not show up in the start menu. However I have noticed that when I get called out to work on computers in the public sector. The clients have recently installed a program like yahoo messenger, or some type of P2P program. These programs have a check box in the options menu that wants them to run (or dial up) the minute windows start's. Try checking that. Hope this works, this is a very annoying, but thats what I check for first.

Are you runnning that damnable Hotbar in your e-mail program (Outlook or Outlook Express). That will instigate a dial up at bootup.

Alan