i want to delete old url from any search engine?

Answer 1

Have a close look at the icons on the tool bar. Can you see a small black upside down triangle at the side of every icon, well if you click on it a drop down menu will appear with all sorts of things on it.
The one you want is on the left of the search box. look for options and personalize your tool bar.
you can also highlight the search and press delete on your keyboard.

http://help.yahoo.com/l/us/yahoo/toolbar/basics/toolbar-10.html

Answer 2

try to delete everything on the temporary file
Tools>Internet Options> click on delete files AND delete cookies
might take quite a while if you haven't done that before.