:roll: Don't ask, not what you think-- at least, that one and some others that I'm thinking of-- try:
Tools > Internet Options > Content; under the section "Personal Information" > AutoComplete... -- Uncheck "Forms" and "User Names and Passwords on Forms" In the same window, under "Clear AutoComplete History" click on "Clear Forms"
I've never tried (obviously,) so just to be on the safe side also do this:
Tools > Internet Options > Advanced;
Uncheck
Browsing > Use Inline AutoComplete