This tells click here how to remove user profiles i.e. logon identities.
To find the dial up password your could try downloading Revealer from click here Install and open the programme.
Then go to Internet Explorer > Tools > Internet Options > Connections tab > Settings and use Revealer to see the password.
If that doesn't work you can go to Outlook Express > Tools > Accounts. Select your account and click 'export'. Save the .iaf file on floppy. To reinstall the account settings go to the same place in OE and import the file from the floppy. This will install the settings complete with password.