http://www.ntlworld.com/help/windowsxp/dialup.htm

Take a look at that page. Scroll down and tell me did you follow the procedure exactly as it says for setting up OE 6 with NTL email.

I am not sure why you need the NTL disk to setup email in Outlook Express 6?? That is the part that is confusing me. I usually set it up manually adding the username password, pop3 and SMTP servers manually.

Hope that helps.