Dial-up Problem

I’ve an XP Home Edition pc which can’t dial my ISP. I have one dial-up connection which works but any others I make give me a ” bad username or password ” error when it authenticates with the ISP server (BTOpenworld.com). I’ve tried downloading bothins files and exe files which make the dial-up for me but I get the same error each time as I do if I make the connecton manually. If I use the Dial-up conection which works Outlook Express can recieve mail ok but can’t send – giving me a server timed out error (presumably server not authenticating properly ie bad username or password again)! Ive been through MS Kb and have checked all the security and CHAP settings but their all as they should be. Username and password are correct as everything works fine on my 98 machine.

Any ideas?