How to 'un-remember' ISA password?

I entered user= isa\administrator and the admin password and checked 'remember' on a user's pc when a dialog box appeared.  

Now, I can't reach the internet on this user's pc.

Normally (and the way it was working before I messed this up), was that the user logs into active directory, and we have isa7 (our isa server) configured in control panel, internet options, connection tab.

It is configured as a pass through (the user does not have to re-enter the userid/password to surf the web).

Now, it seems to be ignoring the pass through credentials of the user and is instead trying to use the local administrator account for web surfing, and it's not setup to do that.

How do I undo this?

I should mention this whole thing started when I was trying to resolve a problem where crystal reports 2008 suddenly, and for 3 users, would not launch (only hour glass).  After about 15 minutes, a window would pop up and ask for a isa userid & password.  I assumed that maybe there was some kind of hard coded phone-home thing in crystal, and because it's not proxy aware, it wanted credentials.  I tried my user's userid & password, but it didn't work.  That's when I tried local administrator on isa and that password.  It solved the crystal problem, so I check 'remember me'.  So, it's not asking any more, and now is messing up pass through  credentials to isa.

Hope this all makes sense,

Any tips would be greatly appreciated.

Thanks,
Mike