Why don't you:
Check your email now:
Disconnected as soon as username & password is verified?

Check WINS configuration is disabled. See our help page located here
Check number dialled. If you are using a non-K56 modem on a K56 line,
this may be the reason.

Disconnected within fixed period of time (i.e. 20 mins)

Check for timeouts set in browser.
Check for timeouts set in modem properties.
Check number dialled and make/speed of modem and ensure compatibility.
If you have call waiting enabled on your line, ensure that it is disabled before
connecting to us. The "bleep" on the line when a second call comes through
will disconnect your modem.

Password is not being accepted and is requested again and again

Check for CAPS lock being on.
Check for capital letters in username and/or password.
Check for @freeuk.net in username and delete @freeuk.net if present.
Check that, if you use a Windows logon, the box is not asking you for this logon
rather than your FreeUK logon.

Unable to negotiate dial-in connection (failed) (Win 3.x)

Check installed modem is correct.
If standard modem, try changing init string to AT&F in modems2.ini file.
Check for line noise and quality.
Check for length of telephone extension cable (long cables can result
in deterioration of signal).

Cannot find any sites with browser

Has the "connect to" box appeared?
Have you heard the modem connecting?
Check for IP address set in either TCP/IP or DUN properties.
Check to ensure that the DNS settings are correct in TCP/IP properties.
See our page for setting up Dial Up Networking for information on how to
get to these settings.

Call to undefined Dynalink

Microsoft Office Toolbar running when Internet Explorer installed.