Just try to keep things simple to start with.
Open Outlook Express. Go to Tools > Accounts > Add > Mail.
Create a new account using the following information:
For your username, enter your
full Talktalk email address. e.g. if your email address is
[email protected], enter exactly that (and not just 'imhotep').
When you enter your password, remember that it's case-dependent, e.g. 'mypassword' is not the same as 'Mypassword'. Take care to type it carefully.
For the outgoing server enter smtp.talktalk.net
For the incoming server enter mail.talktalk.net
That should do the trick. I've fixed lots of problems with Outlook Express (both on my own PCs and on those of others) by simply re-creating the mail accounts. However, in just one case (when trying to solve a problem for an elderly friend) creating a fresh account didn't work. I was certain that the problem was with her ISP's server (which wasn't recognising her password), rather than with the Outlook Express settings on her PC. The ISP's helpline required a lot of persuading that the fault could be at their end of the system but they eventually agreed to check and, finally, accepted that they needed to correct a fault. Perhaps you're in a similar position? If so, try speaking to Talktalk on 0870 0875562. (If they can't help on that number, try 0871 226 7146 instead).
Chris