Please post more and give us all a clearer explanation of your prob.
Outlook Express is for email, are you now using a different prog for email?
IMHO [In My Humble Opinion] To get rid of/ or stop your old dialup connection you need to delete it in 'Network Connections' (in Control Panel)
and while you are in there set your new connection to be the Default Connection so your PC will use that.
hope this is of some use :)