To modify your settings for the AutoComplete feature or clear all items from
the list of form or password suggestions, follow these steps in Internet
Explorer:
1.On the Tools menu, click Internet Options.
2.Click the Content tab.
3.Click AutoComplete.
4.Click the appropriate AutoComplete check boxes, or click Clear Forms or
Clear Passwords to clear all saved items from the appropriate AutoComplete
history.
5.Click OK, and then click OK.
To clear individual items from the list of form or password suggestions,
click the item in the list of suggestions for that field and then press
DELETE. The AutoComplete list automatically appears when you perform any of
the following actions on a previously populated form:
* Type the first character in the field
* Press the UP or DOWN keys in the field
* Double-click a blank area in the field
Source:
How to use the AutoComplete feature in Internet Explorer 5 and 6:
http://support.microsoft.com/?kbid=217148
Related:
Internet Explorer: Save Time with AutoComplete:
http://www.microsoft.com/windows/ie/using/howto/customizing/autocomplete.mspx
Delete the History folder and index.dat:
http://www.mvps.org/winhelp2002/delcache.htm