There's an occasional problem with Internet Explorer when accessing a password-protected site.
When you try to access the first time, a box pops up which asks for the username and password, and there's a check box to tell it to remember that username and password. Almost every time, this works fine. But occasionally (I'm not sure the cause) it stores the wrong password. This is a pretty rare problem, but I've seen it a number of times.
If you're using version 5, then go to Tools ... Internet options ... content ... click on autocomplete ... click on "Clear passwords". That will tell it to forget *all* your passwords. Close down Explorer, then start it up again.
If you're using version 6, then go to Tools ... Internet options ... content ... click on autocomplete ... click on "Clear passwords". That will tell it to forget *all* your passwords. Close down Explorer, then start it up again.
As far as I can tell, there's no way in Internet Explorer to tell it "forget that password, it's wrong, here's the right one".
So, where is it storing that password? If your Windows login is "bloggs", then the file it's using is c:\windows\bloggs.pwl and it's easy to see that this is so, because if you give it another password to store, that file changes and has a file time that shows the time you just updated the password. But if you look at the file, you'll see it's encrypted (as you'd expect) so that people can't just steal your passwords.
This means that the only way of correcting it, is to delete that file. But that tells Windows to forget *all* your passwords, so that means that ever password that's been filled in for you automatically, will have to be given again. So you shouldn't do this if there's some passwords that you need, but you don't have them written down someplace.
Another alternative is to re-install Internet Explorer, but if you do that, it might not initialise your passwords.
A third alternative is to ask me to set up a new username and password for you. This will mean that the fact that it has the old one wrong, shouldn't matter.