Vista - Problems switching from broadband back to LAN

Hello all,
I am having a hell of a time switching my email from broadband back to LAN.
I uninstalled Norton, and am running with Avast. When I click on WM, I get a
message saying Dial up connection...connect, settings, or cancel, I select
cancel because I have already set up a second account to check my mail. I can
recieve messages but I am having trouble sending, sometimes I have to resend
it to get it sent. If I delete this current account will my secondary account
save all my old addresses, messages etc... I am getting sick of having to
deal with this pop-up all the time. Under Mail...Accounts...I try to select
connections to change my setting back to LAN but if I select connections, my
WM freezes and I have to shut my email down and restart it. Thanks so much,

Misty