dial-up window pops up uncalled

the window I use to start the telephone call to my
internet provider pops up erratically, especially but not
only when running IE and/or outlook express. When it pops
up while running Myst, it crashes that game. It pops up,
often, when closing down the machine, as well as when
booting up. I wish I could stop this. Whatever calls this
window has a nervous trigger finger. It seems that a
slight mouse movement does it, sometimes after a few
second delay. Thanks for any help. Larry