Okay, a lot of information to get through here...

Corporate proxy server has authentication. It is changing the authentication from one domain to a new one. At the moment, both domains are active, but the old one will disappear soon. The usernames and passwords are the same on both domains. I want to have my users change their domain but not their username and password when they authenticate with the proxy server.

Note that my users are not on either of those domains. Their local boxes are logging into a third unrelated domain. So. When they run IE, the proxy prompts for their username and password instead of getting it automatically from their current login. Like so:

OldCorporateDomain\Username
Password

(Or, depending on how the box is laid out, it might be...)

Username
Password
OldCorporateDomain

Then they can get to the 'net through the proxy during that session of IE.

If they can click their little "Remember password" checkbox then they don't have to enter their password every time they re-launch IE.

Now here's the trick:

On windows 2000, that "remember password" thing still prompts them, the password is just pre-filled in. So. My windows 2000 users have no trouble changing their domain.

But the XP users do have a problem. On windows XP, the "remember password" thing means they never get prompted again unless the password goes bad on the server side. I want the XP users to get prompted again. They're not getting prompted. How do I make it prompt them again?

I've tried the following:

Tools/Internet Options/Content/AutoComplete/Click on "Clear Passwords". This, inexplicably, LOCKS UP IE COMPLETELY on the one user's box that I was using as my test case. ARGH. Passwords do not get cleared because of this lockup. And besides, I'd prefer that the passwords be kept and just the domain changed.

Tools/Internet Options/Content/AutoComplete/Uncheck all three boxes under "Use AutoComplete For", then restart IE. No change, it still automatically logs into the proxy server without prompting.

Does anyone know how to make it prompt, or, failing that, what fricking file I need to erase in order to make it forget the IE saved password for the proxy server?

[MS Technician]Reinstall Windows[/MS Technician]

Control Panel -> User Accounts -> Select-a-user -> Manage my network passwords

It one of those?

Yup, that was it, exactly. I can even edit the domain name there directly without erasing the username and password.

Thanks Trevor, you are The Man.